Methods of Making and Structures Containing Stiffeners Having Transition Portions

ABSTRACT

A stiffener  100  comprises a first stiffener portion ( 102 ), having a first cross-sectional profile ( 104 ) that is constant along the first stiffener portion ( 102 ). The stiffener  100  also comprises a second stiffener portion ( 106 ), having a second cross-sectional profile ( 108 ) that is constant along the second stiffener portion ( 106 ). The second cross-sectional profile ( 108 ) of the second stiffener portion ( 106 ) is different from the first cross-sectional profile ( 104 ) of the first stiffener portion ( 102 ). The stiffener  100  additionally comprises a transition stiffener portion ( 110 ) tapering from the second stiffener portion ( 106 ) to the first stiffener portion ( 102 ).

BACKGROUND

Aerodynamic loads experienced by aircraft structures, such as anaircraft wing, include, e.g., bending loads. Tough and lightweightcomposite materials are increasingly used in the construction ofaircraft wings because they are capable of supporting the loadsencountered during flight while enabling a decrease in weight of theaircraft. A common type of composite material used in aircraftconstruction is carbon fiber composite.

Generally, a wingbox structure of the aircraft wing includes a stiffenedupper panel (or skin), a stiffened lower panel (or skin), opposed sparsthat connect to leading and trailing edges of the panels, and internalribs that provide shape and support to the wingbox structure and connectthe panels. It is desirable to decrease the thickness of the wing,particularly an outboard portion of the wing, as much as possible toimprove the aerodynamic efficiency of the aircraft (e.g., a thicker wingencounters more drag). However, decreasing wing thickness continues tobe a structural challenge because the height of the stiffeners limitshow thin the wing can be constructed in view of the fact that the use ofstiffeners having a reduced height to decrease wing thickness islimited. Low-profile stiffeners may be used to stiffen the lower panelsince the lower panel is primarily in tension during flight. However,low profile-stiffeners are not suitable for the upper panel.High-profile stiffeners (e.g., stiffeners having a tallercross-sectional profile), such as I-shaped or T-shaped stiffeners, areneeded to stiffen at least the majority of the upper panel since theupper panel is primary in compression during flight.

SUMMARY

Accordingly, apparatuses and methods, intended to address at least theabove-identified concerns, would find utility.

The following is a non-exhaustive list of examples, which may or may notbe claimed, of the subject matter according the present disclosure.

One example of the present disclosure relates to a stiffener. Thestiffener comprises a first stiffener portion having a firstcross-sectional profile that is constant along the first stiffenerportion. The stiffener also comprises a second stiffener portion havinga second cross-sectional profile that is constant along the secondstiffener portion. The second cross-sectional profile of the secondstiffener portion is different from the first cross-sectional profile ofthe first stiffener portion. The stiffener further comprises atransition stiffener portion tapering from the second stiffener portionto the first stiffener portion.

Another example of the present disclosure relates to a structure. Thestructure comprises a skin, comprising surface, and a stiffener, coupledto the surface of the skin. The stiffener comprises a first stiffenerportion, having a first cross-sectional profile that is constant alongthe first stiffener portion. The stiffener also comprises a secondstiffener portion, having a second cross-sectional profile that isconstant along the second stiffener portion. The second cross-sectionalprofile of the second stiffener portion is different from the firstcross-sectional profile of the first stiffener portion. The stiffenerfurther comprises a transition stiffener portion, tapering from thesecond stiffener portion to the first stiffener portion.

Yet another example of the present disclosure relates to a method ofmaking a stiffener. The method comprises laying up a base charge to forma part of a first stiffener portion of the stiffener from a firstbase-charge portion of the base charge, to form a part of a secondstiffener portion of the stiffener from a second base-charge portion ofthe base charge, and to form a part of a transition stiffener portion ofthe stiffener from a transition base-charge portion of the base charge.The transition base-charge portion tapers from the second base-chargeportion to the first base-charge portion. The method also compriseslaminating an initial charge onto the base charge to form a part of thefirst stiffener portion of the stiffener from a first initial-chargeportion of the initial charge and to form a part of the transitionstiffener portion of the stiffener from a transition initial-chargeportion of the initial charge. The first initial-charge portion of theinitial charge is shaped identically to the first base-charge portion ofthe base charge, and the transition initial-charge portion of initialcharge is shaped identically to at least a portion of the transitionbase-charge portion of the base charge. The method further compriseslaminating a subsequent charge A onto the initial charge to form a partof the first stiffener portion of the stiffener from a firstsubsequent-charge-A portion of the subsequent charge A and to form apart of the transition stiffener portion of the stiffener from atransition subsequent-charge-A portion of the subsequent charge A. Thefirst subsequent-charge-A portion of the subsequent charge A is shapedidentically to the first initial-charge portion of the initial charge,and the transition subsequent-charge-A portion of the subsequent chargeA is smaller than the transition initial-charge portion of the initialcharge and is shaped identically to a portion of the transitioninitial-charge portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described examples of the present disclosure in generalterms, reference will now be made to the accompanying drawings, whichare not necessarily drawn to scale, and wherein like referencecharacters designate the same or similar parts throughout the severalviews, and wherein:

FIG. 1A is a first portion of a block diagram of a structure and astiffener, according to one or more examples of the present disclosure;

FIG. 1B is a second portion of the block diagram of the structure andthe stiffener, according to one or more examples of the presentdisclosure;

FIG. 2 is a schematic, side elevation view of the stiffener of FIGS. 1Aand 1B, according to one or more examples of the present disclosure;

FIG. 3 is a schematic, top plan view of the stiffener of FIGS. 1A and1B, according to one or more examples of the present disclosure;

FIG. 4 is a schematic, first end perspective view of the stiffener ofFIGS. 1A and 1B, according to one or more examples of the presentdisclosure;

FIG. 5 is a schematic, second end perspective view of the stiffener ofFIGS. 1A and 1B, according to one or more examples of the presentdisclosure;

FIG. 6 is a schematic, section view of a second stiffener portion of thestiffener of FIGS. 1A and 1B, according to one or more examples of thepresent disclosure;

FIG. 7 is a schematic, section view of the second stiffener portion ofthe stiffener of FIGS. 1A and 1B, according to one or more examples ofthe present disclosure;

FIG. 8 is a schematic, section view of a first stiffener portion of thestiffener of FIGS. 1A and 1B, according to one or more examples of thepresent disclosure;

FIG. 9 is a schematic, section view of a transition stiffener portion ofthe stiffener of FIGS. 1A and 1B, according to one or more examples ofthe present disclosure;

FIG. 10 is a schematic, section view of the transition stiffener portionof the stiffener of FIGS. 1A and 1B, according to one or more examplesof the present disclosure;

FIG. 11 is a schematic, section view of the transition stiffener portionof the stiffener of FIGS. 1A and 1B, according to one or more examplesof the present disclosure;

FIG. 12 is a schematic, perspective view of a base charge of thestiffener of FIGS. 1A and 1B, according to one or more examples of thepresent disclosure;

FIG. 13 is a schematic, perspective view of charges, including the basecharge and an initial charge, of the stiffener of FIGS. 1A and 1B,according to one or more examples of the present disclosure;

FIG. 14 is a schematic, perspective view of the charges, including thebase charge, the initial charge, and a subsequent charge A, of thestiffener of FIGS. 1A and 1B, according to one or more examples of thepresent disclosure;

FIG. 15 is a schematic, perspective view of the charges, including thebase charge, the initial charge, the subsequent charge A, and asubsequent charge B, of the stiffener of FIGS. 1A and 1B, according toone or more examples of the present disclosure;

FIG. 16 is a schematic, perspective view of the charges, including thebase charge, the initial charge, the subsequent charge A, and subsequentcharges B through N of the stiffener of FIGS. 1A and 1B, according toone or more examples of the present disclosure;

FIG. 17 is a schematic, perspective view of a smooth transition of thecharges, including the base charge, the initial charge, the subsequentcharge A, and the subsequent charges B through N, of the stiffener ofFIGS. 1A and 1B, according to one or more examples of the presentdisclosure;

FIG. 18 is a schematic, perspective view of a cover layer covering thecharges of the stiffener of FIGS. 1A and 1B, according to one or moreexamples of the present disclosure;

FIG. 19 is a schematic, perspective view of the charges and a fillercharge of the stiffener of FIGS. 1A and 1B, according to one or moreexamples of the present disclosure;

FIG. 20 is a schematic, perspective view of the charges, the fillercharge and a web charge of the stiffener of FIGS. 1A and 1B, accordingto one or more examples of the present disclosure;

FIG. 21 is a schematic, perspective view of the charges, the fillercharge, the web charge and an opposing web charge of the stiffener ofFIGS. 1A and 1B, according to one or more examples of the presentdisclosure;

FIG. 22 is a schematic, perspective view of the charges and a web of thestiffener of FIGS. 1A and 1B, according to one or more examples of thepresent disclosure;

FIG. 23 is a schematic, side elevation view of the structure of FIGS. 1Aand 1B, according to one or more examples of the present disclosure;

FIG. 24 is a schematic, top plan view of an aircraft comprising thestructure of FIGS. 1A and 1B, according to one or more examples of thepresent disclosure;

FIG. 25A is a first portion of a block diagram of a method of making astiffener, according to one or more examples of the present disclosure;

FIG. 25B is a second portion of a block diagram of a method of makingthe stiffener, according to one or more examples of the presentdisclosure;

FIG. 26 is a block diagram of aircraft production and servicemethodology; and

FIG. 27 is a schematic illustration of an aircraft.

DETAILED DESCRIPTION

In FIGS. 1A and 1B, referred to above, solid lines, if any, connectingvarious elements and/or components may represent mechanical, electrical,fluid, optical, electromagnetic and other couplings and/or combinationsthereof. As used herein, “coupled” means associated directly as well asindirectly. For example, a member A may be directly associated with amember B, or may be indirectly associated therewith, e.g., via anothermember C. It will be understood that not all relationships among thevarious disclosed elements are necessarily represented. Accordingly,couplings other than those depicted in the block diagrams may alsoexist. Dashed lines, if any, connecting blocks designating the variouselements and/or components represent couplings similar in function andpurpose to those represented by solid lines; however, couplingsrepresented by the dashed lines may either be selectively provided ormay relate to alternative examples of the present disclosure. Likewise,elements and/or components, if any, represented with dashed lines,indicate alternative examples of the present disclosure. One or moreelements shown in solid and/or dashed lines may be omitted from aparticular example without departing from the scope of the presentdisclosure. Environmental elements, if any, are represented with dottedlines. Virtual (imaginary) elements may also be shown for clarity. Thoseskilled in the art will appreciate that some of the features illustratedin FIGS. 1A and 1B may be combined in various ways without the need toinclude other features described in FIGS. 1A and 1B, other drawingfigures, and/or the accompanying disclosure, even though suchcombination or combinations are not explicitly illustrated herein.Similarly, additional features not limited to the examples presented,may be combined with some or all of the features shown and describedherein.

In FIGS. 25A, 25B and 26, referred to above, the blocks may representoperations and/or portions thereof and lines connecting the variousblocks do not imply any particular order or dependency of the operationsor portions thereof. Blocks represented by dashed lines indicatealternative operations and/or portions thereof. Dashed lines, if any,connecting the various blocks represent alternative dependencies of theoperations or portions thereof. It will be understood that not alldependencies among the various disclosed operations are necessarilyrepresented. FIGS. 25A, 25B and 26 and the accompanying disclosuredescribing the operations of the method(s) set forth herein should notbe interpreted as necessarily determining a sequence in which theoperations are to be performed. Rather, although one illustrative orderis indicated, it is to be understood that the sequence of the operationsmay be modified when appropriate. Accordingly, certain operations may beperformed in a different order or simultaneously. Additionally, thoseskilled in the art will appreciate that not all operations describedneed be performed.

In the following description, numerous specific details are set forth toprovide a thorough understanding of the disclosed concepts, which may bepracticed without some or all of these particulars. In other instances,details of known devices and/or processes have been omitted to avoidunnecessarily obscuring the disclosure. While some concepts will bedescribed in conjunction with specific examples, it will be understoodthat these examples are not intended to be limiting.

Unless otherwise indicated, the terms “first,” “second,” etc. are usedherein merely as labels, and are not intended to impose ordinal,positional, or hierarchical requirements on the items to which theseterms refer. Moreover, reference to, e.g., a “second” item does notrequire or preclude the existence of, e.g., a “first” or lower-numbereditem, and/or, e.g., a “third” or higher-numbered item.

Reference herein to “one example” means that one or more feature,structure, or characteristic described in connection with the example isincluded in at least one implementation. The phrase “one example” invarious places in the specification may or may not be referring to thesame example.

Illustrative, non-exhaustive examples, which may or may not be claimed,of the subject matter according the present disclosure are providedbelow.

Referring, e.g., to FIGS. 1A, 1B, 2-5 and 22, stiffener 100, isdisclosed. Stiffener 100 comprises first stiffener portion 102, havingfirst cross-sectional profile 104 that is constant along first stiffenerportion 102. Stiffener 100 also comprises second stiffener portion 106,having second cross-sectional profile 108 that is constant along secondstiffener portion 106. Second cross-sectional profile 108 of secondstiffener portion 106 is different from first cross-sectional profile104 of first stiffener portion 102. Stiffener 100 further comprisestransition stiffener portion 110, tapering from second stiffener portion106 to first stiffener portion 102. The preceding subject matter of thisparagraph characterizes example 1 of the present disclosure.

First stiffener portion 102 and second stiffener portion 106 enable asingle continuous stiffener 100 to have different cross-sectionalprofiles and/or dimensions, which provide different structuralcharacteristics, for example, size, shape and/or load bearingcharacteristics. Transition stiffener portion 110 effectively transfersa load between first stiffer portion 102 and second stiffener portion106.

Gradually shifting (e.g., tapering) from first cross-sectional profile104 of first stiffener portion 102 to second cross-sectional profile 108of second stiffener portion 106 along transition stiffener portion 110provides a more effective load transfer as compared to abutting,splicing or otherwise coupling two different stiffeners each having adifferent cross-sectional profile.

First cross-sectional profile 104 may have any suitable shape dependingupon the particular structural application of stiffener 100, forexample, when used to construct structure 200 (e.g., FIG. 1A). As oneexample, first cross-sectional profile 104 of first stiffener portion102 may be designed to react to bending loads, such as wing bendingloads experienced during flight. As one example, the bending loads areprimarily tension-driven loads.

Similarly, second cross-sectional profile 108 may have any suitableshape (e.g., different than the shape of first cross-sectional profile104) depending upon the particular structural application of stiffener100, for example, when used to construct structure 200. As one example,second cross-sectional 108 of second stiffener portion 106 may bedesigned to react to bending loads, such as wing bending loadsexperienced during flight. As one example, the bending loads areprimarily compression-driven loads.

As will be described in more detail below, as one example, stiffener 100enables construction of aircraft wing 206 (e.g., FIG. 24), for example,an outboard portion of wing 206, having a relatively thincross-sectional profile, which provides significant aerodynamicbenefits, while allowing sufficient clearance between upper and lowerstiffeners about the outboard portion.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.4, 5, and 8, first cross-sectional profile 104 of first stiffenerportion 102 is trapezoidally shaped. The preceding subject matter ofthis paragraph characterizes example 2 of the present disclosure,wherein example 2 also includes the subject matter according to example1, above.

A trapezoidally shaped first cross-sectional profile 104 of firststiffener portion 102 of stiffener 100 enables first stiffener portion102 to suitably react to bending loads primarily due to tension loading,while also providing a relatively short profile height.

When stiffener 100 is used to construct structure 200 (e.g., wing 206)(FIG. 1A), the trapezoidally shaped first cross-sectional profile 104 offirst stringer portion 102 provides for an increase in the availableclearance space between first stiffener portion 102 of stiffener 100 andan opposing structural component (e.g., an opposed stiffener).

When used in the construction of wing 206 of aircraft 208 (e.g., FIG.24), the trapezoidally shaped first cross-sectional profile 104 of firststiffener portion 102 of stiffener 100 may also be known as a plank-typestringer.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.4-6, second cross-sectional profile 108 of second stiffener portion 106is T-shaped. The preceding subject matter of this paragraphcharacterizes example 3 of the present disclosure, wherein example 3also includes the subject matter according to any one of examples 1 or2, above.

A T-shaped second-cross sectional profile 108 of second stiffenerportion 106 of stiffener 100 enables second stiffener portion 106 tosuitably react to bending loads primarily due to compression loading,while also providing a relatively tall profile height and/or a highcross-sectional moment of inertia.

As used herein, the term “T-shaped” refers to a shaped member having afirst (e.g., substantially vertical) portion and a second (e.g.,substantially horizontal) portion substantially perpendicularly coupledto an end of the first portion. The second portion extends laterallyoutward in opposite directions, for example, equidistantly, from the endof the first portion.

When used in the construction of wing 206 of aircraft 208 (e.g., FIG.24), the T-shaped second cross-sectional profile 108 of second stiffenerportion 106 of stiffener 100 may also be known as a blade-type stringer.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.7, second cross-sectional profile 108 of second stiffener portion 106 isI-shaped. The preceding subject matter of this paragraph characterizesexample 4 of the present disclosure, wherein example 4 also includes thesubject matter according to any one of examples 1 or 2, above.

An I-shaped second cross-sectional profile 108 of second stiffenerportion 106 of stiffener 100 enables second stiffener portion 106 tosuitably react to bending loads primarily due to compression loading,while also providing a relatively tall profile height and/or a highcross-section moment of inertia.

As used herein, the term “I-shaped” refers to a shaped member having afirst (e.g., substantially vertical) portion, a second (e.g.,substantially horizontal) portion substantially perpendicularly coupledto a first end of the first portion, and a third (e.g., substantiallyhorizontal) portion substantially perpendicularly coupled to a secondend (opposite the first end) of the first portion. The second portionextends laterally outward in opposite directions, for example,equidistantly, from the first end of the first portion. The thirdportion extends laterally outward in opposite directions, for example,equidistantly, from the second end of the first portion.

When used in the construction of wing 206 of aircraft 208 (e.g., FIG.24), the I-shaped second cross-sectional profile 108 of second stiffenerportion 106 of stiffener 100 may also be known as an I-type stringer.

Referring generally to FIGS. 1A, 1B, 2 and 3 and particularly to, e.g.,FIGS. 4,5 and 9-11, transition stiffener portion 110 comprisestransition cross-sectional profiles 112. Transitional cross-sectionalprofiles 112 of transition stiffener portion 110 are different fromfirst cross-sectional profile 104 of first stiffener portion 102 andsecond cross-sectional profile 108 of second stiffener portion 106. Thepreceding subject matter of this paragraph characterizes example 5 ofthe present disclosure, wherein example 5 also includes the subjectmatter according to any one of examples 1-4, above.

Transition cross-sectional profiles 112 of transition stiffener portion110 gradually shifting (e.g., transitioning) from first cross-sectionalprofile 104 of first stiffener portion 102 to second cross-sectionalprofile 108 of second stiffener portion 106 to provides effective loadtransfer between first stiffener portion 102 and second stiffenerportion 106 through transition stiffener portion 110.

Each one of transition cross-sectional profiles 112 of transitionstiffener portion 110 has a shape representing a transformation betweenfirst cross-sectional profile 104 of first stiffener portion 102 andsecond cross-sectional profile 108 of second stiffener portion 106.Transition cross-sectional profiles 112 proximate (e.g., at or near)first stiffener portion 102 have shapes approximating firstcross-sectional profile 104. Similarly, transition cross-sectionalprofiles 112 proximate (e.g., at or near) second stiffener portion 106have shapes approximating second cross-sectional profile 108.

As one example, and as best illustrated in FIGS. 4 and 5, transitioncross-sectional profiles 112 have shapes transitioning between atrapezoidal shape (e.g., first cross-sectional profile 104) and aT-shape (e.g., second cross-sectional profile 108).

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 9-11, all of transitional cross-sectional profiles 112 oftransition stiffener portion 110 are different. The preceding subjectmatter of this paragraph characterizes example 6 of the presentdisclosure, wherein example 6 also includes the subject matter accordingto example 5, above.

All of transition cross-sectional profiles 112 of transition stiffenerportion 110 being different provide a consistent and continualtransition (e.g., ramp rate) between first cross-sectional profile 104of first stiffener portion 102 and second cross-sectional profile 108 ofsecond stiffener portion 106 (e.g., from second cross-sectional profile108 of second stiffener portion 106 to first cross-sectional profile 104of first stiffener portion 102 or from first cross-sectional profile 104of first stiffener portion 102 to second cross-sectional profile 108 ofsecond stiffener portion 106).

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 9-11, transition cross-sectional profiles 112 smoothlytransition from second cross-sectional profile 108 of second stiffenerportion 106 to first cross-sectional profile 104 of first stiffenerportion 102. The preceding subject matter of this paragraphcharacterizes example 7 of the present disclosure, wherein example 7also includes the subject matter according to example 6, above.

A smooth transition between first cross-sectional profile 104 and secondcross-sectional profile 108 along transition cross-sectional profiles112 gradually changes the centroid of stiffener 100 and reduces thepotential of stiffener 100 pulling off of a panel to which it iscoupled.

Abrupt changes to the centroid of stiffener 100 may increase thepotential of stiffener 100 pulling away from the panel to which it iscoupled. The smooth transition of transition cross-sectional profiles112 of transition stiffener portion 110 between first cross-sectionalprofile 104 of first stiffener portion 102 and second cross-sectionalprofile 108 of second stiffener portion 106 (e.g., from secondcross-sectional profile 108 of second stiffener portion 106 to firstcross-sectional profile 104 of first stiffener portion 102 or from firstcross-sectional profile 104 of first stiffener portion 102 to secondcross-sectional profile 108 of second stiffener portion 106) moreeffectively transfers loads between first stiffener portion 102 andsecond stiffener portion 106.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.6-11 and 13-22, stiffener 100 further comprises charges 160 laminatedtogether to form first stiffener portion 102, a part of second stiffenerportion 106, and a part of transition stiffener portion 110. Thepreceding subject matter of this paragraph characterizes example 8 ofthe present disclosure, wherein example 8 also includes the subjectmatter according to any one of examples 1-7, above.

Charges 160 that are stacked and laminated together form an integral,continuous part of stiffener 100 capable of effectively transferringloads between first stiffener portion 102 and second stiffener portion106 along transition stiffener portion 110.

Charges 160 may be formed from a composite material. For example, thecomposite material may include reinforcing fibers and resins. As oneexample, each of charges 160 may be a carbon fiber composite. Types ofcarbon fiber composites used to form charges 100 include pre-impregnated(“prepreg”) thermoset composite, dry fiber thermoset composite, andthermoplastic composite. The laminated stack of charges 160 may be cured(e.g., co-cured) to form first stiffener portion 102, the part of secondstiffener portion 106, and the part of transition stiffener portion 110.

As used herein, the terms laminated, laminating, etc. generally refer tooverlaying, stacking, bundling, arranging, placing or otherwisepositioning one or more layers relative to one or more additional layersand, optionally, securing those layers together.

As one example, and as best illustrated in FIGS. 6-11, each one ofcharges 160 may have a trapezoidal cross-sectional shape. Firststiffener portion 102 is formed from a trapezoidal stack of charges 160.The part of second stiffener portion 106 is formed from a trapezoidalstack of charges 160. The part of transition stiffener portion 110 isformed from a trapezoidal stack of charges 160.

A different number of charges 160 are used to form each of firststiffener portion 102, second stiffener portion 106, and transitionstiffener portion 110. As one example, a fewer number of charges 160 areused to form the part of second stiffener portion 106 and a greaternumber of charges 160 are used to form first stiffener portion 102. Thenumber of charges 160 used to from the part of transition stiffenerportion 110 increases from the fewer number (e.g., of the secondstiffener portion 106) to the greater number (e.g., of the firststiffener portion 102).

Any suitable number of charges 160 may be used to form first stiffenerportion 102, the part of second stiffener portion 106, and the part oftransition stiffener portion 110. As one example, and as bestillustrated in FIGS. 6-11, five charges 160 may be used. As one example,and as best illustrated in FIG. 15, four charges 160 may be used. As oneexample, and as best illustrated in FIG. 16, seven charges 160 may beused. Additional charges may also be used without limitation.

As one specific example, and as best illustrated in FIG. 16, one ofcharges 160 (e.g., base charge 126) may form the part of secondstiffener portion 106. One of charges 160 and another one of charges 160(e.g., initial charge 148) may form one portion of the part oftransition stiffener portion 110. One of charges 160, another one ofcharges 160, and yet another one of charges 160 (e.g., subsequent chargeA) may form another portion of the part of transition stiffener portion110. One of charges 160, another one of charges 160, yet another one ofcharges 160, and additional ones of charges 160 (e.g., subsequentcharges B through N) may form additional portions of the part oftransition stiffener portion 110. One of charges 160, another one ofcharges 160, yet another one of charges 160, and additional ones ofcharges 160 may form first stiffener portion 102.

Referring to FIGS. 1A and 1B, stiffener 100 further comprises prepregcomposite plies 126 laminated together to form each one of charges 160.Prepreg composite plies 126 comprise reinforcement fibers 240.Reinforcement fibers 240 of approximately fifty percent of prepregcomposite plies 126 are parallel to a primary load direction ofstiffener 100. Reinforcement fibers 240 of approximately forty percentof prepreg composite plies 126 are at forty-five degrees to the primaryload direction of stiffener 100. Reinforcement fibers 240 ofapproximately ten percent of prepreg composite plies 126 areperpendicular to the primary load direction of stiffener 100. Thepreceding subject matter of this paragraph characterizes example 9 ofthe present disclosure, wherein example 9 also includes the subjectmatter according to example 8, above.

Varying and/or alternating the orientation of reinforcing fibers 240among prepreg composite plies 126, with respect to a longitudinal axisof each one of charges 160, at a plurality of different angles, such asapproximate angles of 0-degrees, −45-degrees, 90-degrees, and45-degrees, produces optimum mechanical properties (e.g., strengthand/or stiffness) in charges 160 and stiffener 100 formed from charges160.

Prepreg composite plies 126 may correspond to an uncured configurationof plies forming each one of charges 160, which when cured may formfirst stiffener portion 102, part of second stiffener portion 106, andpart of transition stiffener portion 110. For example, prepreg compositeplies 126 may correspond to a plurality of generally planar carbon fiberprepreg plies with various angular orientations. Each of prepregcomposite plies 126 is stronger along the direction of orientation ofreinforcing fibers 240 and weaker in a direction perpendicular toreinforcing fibers 240.

As described above, a stacked and laminated plurality of prepregcomposite plies 126 forms each one of charges 160 and a stacked andlaminated plurality of charges 160 form a part of stiffener 110 (e.g.,first stiffener portion 102, the part of second stiffener portion 106,and the part of transition stiffener portion 110). As one example, eachone of charges 160 may include twenty-two (22) prepreg composite plies126. Prepreg composite plies 126 may have various angular orientationsof reinforcing fibers 240.

Listed below in Table 1 is one example of a configuration of prepregcomposite plies 126 (identified as P1 through P22) used to form a firstgroup of charges 160 used to form the part of stiffener 100 and Table 2is one example of a configuration of prepreg composite plies (identifiedas P1 through P22) used to form a second group of charges 160 used toform the part of stiffener 100.

TABLE 1 PLY ORIENTATION 1 0 2 45 3 0 4 0 5 −45 6 90 7 45 8 0 9 0 10 −4511 0 12 0 13 45 14 0 15 0 16 −45 17 90 18 45 19 0 20 0 21 −45 22 0

TABLE 2 PLY ORIENTATION 1 0 2 −45 3 0 4 0 5 45 6 90 7 −45 8 0 9 0 10 4511 0 12 0 13 −45 14 0 15 0 16 45 17 90 18 −45 19 0 20 0 21 45 22 0

As one example, seven charges 160 may be used to form the part ofstiffener 100. Table 1 illustrates the orientation of reinforcing fibers240 of prepreg composite plies 126 used for a first (e.g., lowermost)one of charges 160, a third one of charges 160, a fifth one of charges160, and a seventh (e.g., uppermost) one of charges 160. Table 2illustrates the orientation of reinforcing fibers 240 of prepregcomposite plies 126 used for a second one of charges 160, a fourth oneof charges 160, and a sixth one of charges 160. As illustrated, theorientation of reinforcing fibers 240 of prepreg composite plies 126 mayalternate between each one of charges 160.

It should be understood that ply counts and orientations in Table 1 andTable 2 are merely exemplary and that other configurations, numbers ofprepreg composite plies, and/or other orientations are contemplated. Asone example, more or less than twenty-two prepreg composite plies 126may be used. As one example, the orientations of the reinforcing fibers240 of prepreg composite plies 126 may vary.

It should also be understood that the number of charges 160 are merelyexemplary and that other numbers of charges are also contemplated. Asone example, more or less than seven charges 160 may be used to form thepart of stiffener 100.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-7, 9-11 and 22, stiffener 100 further comprises web 120. A part ofsecond stiffener portion 106 and a part of transition stiffener portion110 are formed by web 120. Web 120 comprises base 122 and rib 168perpendicular to base 122. Base 122 of web 120 is parallel to charges160. The preceding subject matter of this paragraph characterizesexample 10 of the present disclosure, wherein example 10 also includesthe subject matter according to any one of examples 8 or 9, above.

Base 122 and rib 168 of web 120 enables second stiffener portion 106 andtransition stiffener portion 110 to suitably react to bending loads dueto compression and provides the majority of the height and a part of theshape of second cross-sectional profile 108 of second stiffener portion106 and transition cross-sectional profiles 112 of transition stiffenerportion.

Base 122 of web 120 is stacked on and is cured (e.g., co-cured) orbonded (e.g., co-bonded or secondarily bonded) to charges 160 formingthe part of second stiffener portion 106 and to charges 160 forming thepart of transition stiffener portion 110.

A portion of base 122 and rib 168 of web 120 forming the part of secondstiffener portion 106 may have a constant cross-sectional dimensionalong second stiffener portion 106. A portion of base 122 and rib 168forming the part of transition stiffener portion 110 may have agradually decreasing cross-sectional dimension along transitionstiffener portion 110 from second stiffener portion 106 to firststiffener portion 102.

Web 120 may be formed from a composite material. For example, thecomposite material may include reinforcing fibers and resins. As oneexample, web 120 (e.g., base 122 and rib 168) may be a carbon fibercomposite. Types of carbon fiber composites used to form web 120 includepre-impregnated (“prepreg”) thermoset composite, dry fiber thermosetcomposite, and thermoplastic composite.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 22, web 120 tapers from second stiffener portion 106 to firststiffener portion 102. The preceding subject matter of this paragraphcharacterizes example 11 of the present disclosure, wherein example 11also includes the subject matter according to example 10, above.

Web 120 being tapered from second stiffener portion 106 to firststiffener portion 102 gradually reduces the height of transitioncross-sectional profiles 112 from second stiffener portion 106 to firststiffener portion 102 and effectively transfers loads between firststiffener portion 102 and second stiffener portion 106 along transitionstiffener portion 110.

Referring generally to FIGS. 1A, 1B and 13-16 and particularly to, e.g.,FIGS. 6-11, one of charges 160 has width W1 that gradually decreasesalong transition stiffener portion 110 from second stiffener portion 106to first stiffener portion 102. Charges 160 have combined height H1 thatgradually increases along transition stiffener portion 110 from secondstiffener portion 106 to first stiffener portion 102. The precedingsubject matter of this paragraph characterizes example 12 of the presentdisclosure, wherein example 12 also includes the subject matteraccording to any one of examples 10 or 11, above.

Gradually decreasing width W1 of each one of charges 160 and graduallyincreasing combined height H1 of the stack of charges 160 alongtransition stiffener portion 110 provides for the smooth transition oftransition cross-sectional profiles 112 from second cross-sectionalprofile 108 to first cross-sectional profile 104 and enables effectiveload transfer between second stiffener portion 106 and first stiffenerportion 102 along transition stiffener portion 110.

Width W1 illustrated in FIGS. 6-11 corresponds to the width of alowermost one of charges 160. It should be understood that the width ofeach one of charges 160 successively stacked and laminated on thelowermost one of charges 160 also gradually decreases along transitionstiffener portion 110 from second stiffener portion 106 to firststiffener portion 102.

For example, a width of a portion of each one of charges 160 forming thepart of second stiffener portion 106 is greater than a width of aportion of each one of charges 160 forming first stiffener portion 102and a width of a portion of each one of charges 160 forming the part oftransition stiffener portion 110 gradually decreases from the width ofthe portion of each one of charges 160 forming the part of secondstiffener portion 106 to the width of the portion of each one of charges160 forming first stiffener portion 102. As one example, and asillustrated in FIG. 12, a width of second base-charge portion 144 ofbase charge 124 is greater than a width of first base-charge portion 142of base charge 124. A width of transition base-charge portion 146 ofbase charge 124 gradually decreases from the width of second base-chargeportion 144 to the width of first base-charge portion 142. Asillustrated in FIGS. 13-16, each subsequent one of charges 160 (e.g.,initial charge 148, subsequent charge A, and subsequent charges Bthrough N) has the same gradual decrease in width.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.6-11, base 122 of web 120 has width W2 that progressively decreasesalong transition stiffener portion 110 from second stiffener portion 106to first stiffener portion 102. Rib 168 of web 120 has height H2 thatprogressively decreases along transition stiffener portion 110 fromsecond stiffener portion 106 to first stiffener portion 102. Thepreceding subject matter of this paragraph characterizes example 13 ofthe present disclosure, wherein example 13 also includes the subjectmatter according to example 12, above.

Progressively (e.g., gradually) decreasing width W2 of base 122 of web120 and progressively (e.g., gradually) decreasing height H2 of rib 168of web 120 provides for the smooth transition of transitioncross-sectional profiles 112 from second cross-sectional profile 108 tofirst cross-sectional profile 104 and enables effective load transferbetween second stiffener portion 106 and first stiffener portion 102along transition stiffener portion 110.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 12-14, stiffener 100 further comprises base charge 124,comprising first base-charge portion 142, second base-charge portion144, and transition base-charge portion 146. A part of first stiffenerportion 102 is formed by first base-charge portion 142. A part of secondstiffener portion 106 is formed by second base-charge portion 144. Apart of transition stiffener portion 110 is formed by transitionbase-charge portion 146. Transition base-charge portion 146 of basecharge 124 tapers from second base-charge portion 144 to firstbase-charge portion 142. Stiffener 100 also comprises initial charge 148laminated onto base charge 124. Initial charge 148 comprises firstinitial-charge portion 150 and transition initial-charge portion 152. Apart of first stiffener portion 102 is formed by first initial-chargeportion 150. A part of transition stiffener portion 110 is formed bytransition initial-charge portion 152. First initial-charge portion 150of initial charge 148 is shaped identically to first base-charge portion142 of base charge 124, and transition initial-charge portion 152 ofinitial charge 148 is shaped identically to at least a portion oftransition base-charge portion 146 of base charge 124. Stiffener 100further comprises subsequent charge A laminated onto initial charge 148.Subsequent charge A comprises first subsequent-charge-A portion andtransition subsequent-charge-A portion. A part of first stiffenerportion 102 is formed by first subsequent-charge-A portion. A part oftransition stiffener portion 110 is formed by transitionsubsequent-charge-A portion. First subsequent-charge-A portion ofsubsequent charge A is shaped identically to first initial-chargeportion 150 of initial charge 148. Transition subsequent-charge-Aportion of subsequent charge A is smaller than transition initial-chargeportion 152 of initial charge 148 and is shaped identically to a portionof transition initial-charge portion 152. The preceding subject matterof this paragraph characterizes example 14 of the present disclosure,wherein example 14 also includes the subject matter according to any oneof examples 1-13, above.

A laminated stack of base charge 124, initial charge 148 and subsequentcharge A form an integral, continuous part of stiffener 100 capable ofeffectively reacting to loads (e.g., different bending loads) andtransferring loads between first stiffener portion 102 and secondstiffener portion 106 along transition stiffener portion 110.

Base charge 124, initial charge 148 and subsequent charge A beingsequentially stacked and laminated define combined height H1 (FIGS.8-11) of charges 160, partially defines first cross-sectional profile104 of first stiffener portion 102 and transition cross-sectionalprofiles 112 of transition stiffener portion 110, and enhance theload-carrying capabilities of stiffener 100.

In the examples illustrated in FIGS. 12-22 dashed lines delineate firststiffener portion 102, transition stiffener portion 110 and secondstiffener portion 106. As such, the dashed lines delineate firstbase-charge portion 142, transition base-charge portion 146, and secondbase-charge portion 144 of base charge 124, as illustrated in FIG. 12.Similarly, the dashed lines delineate first initial-charge portion 150and transition initial-charge portion 152 of initial charge 148, asillustrated in FIG. 13. Similarly, the dashed lines delineate firstsubsequent-charge-A portion and transition subsequent-charge-A portionof subsequent charge A, as illustrated in FIG. 14.

Transition base-charge portion 146 of base charge 124 tapering fromsecond base-charge portion 144 to first base-charge portion 146,transition initial-charge portion 152 of initial charge 148 tapering tofirst initial-charge portion 150, transition subsequent-charge-A portionof subsequent charge A tapering to first subsequent-charge-A portiongradually reduces the width of the part of stiffener 100 (e.g., thewidth of the laminated stack of charges 160) from second stiffenerportion 106 to first stiffener portion 102 along transition stiffenerportion 110 and provides for the smooth transition from second stiffenerportion 106 to first stiffener portion 102 along transition stiffenerportion 110.

Transition initial-charge portion 152 of initial charge 148 beingsmaller than transition base-charge portion 146 of base charge 124 andtransition subsequent-charge-A portion of subsequent charge A beingsmaller than transition initial-charge portion 152 of initial charge 148gradually reduces the width of the part of stiffener 100 (e.g., thewidth of the laminated stack of charges 160) from base charge 124 tosubsequent charge A.

Transition initial-charge portion 152 of initial charge 148 being shapedidentically to at least a portion of transition base-charge portion 146of base charge 124 and first subsequent-charge-A portion of subsequentcharge A being shaped identically to first initial-charge portion 150 ofinitial charge 148 and transition subsequent-charge-A portion ofsubsequent charge A being smaller than transition initial-charge portion152 of initial charge 148 and being shaped identically to a portion oftransition initial-charge portion 152 gradually increases the combinedheight of the part of stiffener 100 (e.g., the combined height of thelaminated stack of charges 160) from second stiffener portion 106 tofirst stiffener portion 102 along transition stiffener portion 110.

As one example, and as best illustrated in FIG. 12, second base-chargeportion 144 of base charge 124 has a generally rectangulartwo-dimensional (“2D”) shape. As used herein, the term 2D shape refersto a two-dimensional shape in an orthogonal view. First base-chargeportion 142 of base charge 124 has a generally rectangular 2D shape. Amaximum width of first base-charge portion 142 is smaller than a maximumwidth of second base-charge portion 144. Transition base-charge portion146 of base charge 124 has a trapezoidal 2D shape. A maximum width oftransition base-charge portion 146 gradually decreases from the maximumwidth of first base-charge portion 142 to the maximum width of secondbase-charge portion 144.

As illustrated in FIG. 13, first initial-charge portion 150 of initialcharge 148 has a generally rectangular 2D shape. A maximum width offirst initial-charge portion 150 is smaller than the maximum width offirst base-charge portion 142. Transition initial-charge portion 152 hasa generally trapezoidal 2D shape. A maximum width of transitioninitial-charge portion 152 is smaller than the maximum width oftransition base-charge portion 146. A maximum length of transitioninitial-charge portion 152 may be larger than, equal to, or smaller thana maximum length of transition base-charge portion 146. As one example,and as illustrated in FIG. 13, the length of transition initial-chargeportion 152 is larger than the length of transition base-charge portion146 such that a small portion having a rectangular 2D shape extends oversecond base-charge portion 144.

As illustrated in FIG. 14, first subsequent-charge-A portion ofsubsequent charge A has a generally rectangular 2D shape. A maximumwidth of first subsequent-charge-A portion is smaller than the maximumwidth of first initial-charge portion 150. Transitionsubsequent-charge-A portion has a generally trapezoidal 2D shape. Amaximum width of transition subsequent-charge-A portion is smaller thanthe width of transition initial-charge portion 152. A maximum length oftransition subsequent-charge-A portion is less than the maximum lengthof transition initial-charge portion 152.

As described above, base charge 124, initial charge 148, and subsequentcharge A each have a trapezoidal cross-sectional shape. The stack oftransition base-charge portion 146 of base charge 124, transitioninitial-charge portion 152 of initial charge 148, and transitionsubsequent-charge-A portion of subsequent charge A has a trapezoidalcross-sectional shape. The stack of first base-charge portion 142 ofbase charge 124, first initial-charge portion 150 of initial charge 148,and first subsequent-charge-A portion of subsequent charge A has atrapezoidal cross-sectional shape.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 22, stiffener 100 further comprises web 120. A part of secondstiffener portion 106 and a part of transition stiffener portion 110 areformed by web 120. The preceding subject matter of this paragraphcharacterizes example 15 of the present disclosure, wherein example 15also includes the subject matter according to example 14, above.

Web 120 enables second stiffener portion 106 and transition stiffenerportion 110 to suitably react to bending loads primarily due tocompression and provides the majority of the height of secondcross-sectional profile 108 of second stiffener portion 106 andtransition cross-sectional profiles 112 of transition stiffener portion.

As one example, web 120 is stacked on and is cured (e.g., co-cured) orbonded (e.g., co-bonded or secondarily bonded) to second base-chargeportion 144 of base charge 124 and, optionally, a portion of transitioninitial-charge portion 150 of initial charge 148 to form the part ofsecond stiffener portion 106 and to a portion of transitioninitial-charge portion 150 of initial charge 148 and transitionsubsequent-charge-A portion of subsequent charge A to form the part oftransition stiffener portion 110.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.18-21, stiffener 100 further comprises cover layer 176 between web 120and subsequent charge A, initial charge 148, and base charge 124. Coverlayer 176 covers first stiffener portion 102, formed, at leastpartially, by first base-charge portion 142 of base charge 124, firstinitial-charge portion 150 of initial charge 148, and firstsubsequent-charge-A portion of subsequent charge A. Cover layer 176 alsocovers a part of transition stiffener portion 110, formed, at leastpartially, by transition base-charge portion 146 of base charge 124,transition initial-charge portion 152 of initial charge 148, andtransition subsequent-charge-A portion of subsequent charge A.Additionally, cover layer 176 covers a part of second stiffener portion106, formed, at least partially, by second base-charge portion 144 ofbase charge 124. The preceding subject matter of this paragraphcharacterizes example 16 of the present disclosure, wherein example 16also includes the subject matter according to example 15, above.

Covering (e.g., wrapping) base charge 124, initial charge 148 andsubsequent charge A with cover layer 176 further integrates base charge124, initial charge 148 and subsequent charge A (e.g., charges 160) intoa continuous part of stiffener 100 capable of reacting to bending loadsand transferring loads between first stiffener portion 102 and secondstiffener portion 106.

Cover layer 176 may be formed from a composite material. For example,the composite material may include reinforcing fibers and resins. As oneexample, cover layer 176 may be a carbon fiber composite. Cover layer176 may be flush against exterior surfaces of base charge 124, initialcharge 148 and subsequent charge A. Cover layer 176 may be cured (e.g.,co-cured) or bonded (e.g., co-bonded) with base charge 124, initialcharge 148, subsequent charge A and web 120.

As one example, cover layer 176 may be one ply of carbonfiber-reinforced polymer fabric mesh with fibers oriented in a zero (0)degree direction and a ninety (90) degree direction and woven togetherto form a continuous ply.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 20-22, web 120 comprises web charge 178, comprising secondweb-charge portion 180 and transition web-charge portion 182. A part ofsecond stiffener portion 106 is formed by second web-charge portion 180.A part of transition stiffener portion 110 is formed by transitionweb-charge portion 182. Web 120 also comprises opposing web charge 184,abutting a portion of web charge 178 and comprising secondopposing-web-charge portion 186 and transition opposing-web-chargeportion 188. A part of second stiffener portion 106 is formed by secondopposing-web-charge portion 186. A part of transition stiffener portion110 is formed by transition opposing-web-charge portion 188. Thepreceding subject matter of this paragraph characterizes example 17 ofthe present disclosure, wherein example 17 also includes the subjectmatter according to any one of examples 15 or 16, above.

Web charge 178 and opposing web charge 184 in combination enable secondstiffener portion 106 and transition stiffener portion 110 to suitablyreact to bending loads primarily due to compression and provides themajority of the height and a part of the shape of second cross-sectionalprofile 108 of second stiffener portion 106 and transitioncross-sectional profiles 112 of transition stiffener portion.

Second web-charge portion 180 of web charge 178 and secondopposing-web-charge portion 186 of opposing web charge 184 may bepositioned (e.g., stacked) on second base-charge portion 144 of basecharge 124. Cross-sectional dimensions of second web-charge portion 180of web charge 178 and second opposing-web-charge portion 186 of opposingweb charge 184 may be constant along second base-charge portion 144 ofbase charge 124, for example, to form the part of second stiffenerportion 106.

Transition web-charge portion 182 of web charge 178 and transitionopposing-web-charge portion 188 of opposing web charge 184 may bepositioned (e.g., stacked) on transition initial-charge portion 152 ofinitial charge 148 and transition subsequent-charge-A portion ofsubsequent charge A. Cross-section dimensions of transition web-chargeportion 182 of web charge 178 and transition opposing-web-charge portion188 of opposing web charge 184 may gradually decrease along transitioninitial-charge portion 152 of initial charge 148 and transitionsubsequent-charge-A portion of subsequent charge A, for example, to formthe part of transition stiffener portion 110. The gradual reduction inthe cross-sectional dimensions of transition web-charge portion 182 ofweb charge 178 and transition opposing-web-charge portion 188 ofopposing web charge 184 may taper web 120 along transition stiffenerportion 110.

Web charge 178 and opposing web charge 184 may be formed from acomposite material. For example, the composite material may includereinforcing fibers and resins. As one example, web charge 178 andopposing web charge 184 may be a carbon fiber composite. Web charge 178and opposing web charge 184 of web 120 may be cured (e.g., co-cured)together. Web charge 178 and opposing web charge 184 of web 120 may becured (e.g., co-cured) or bonded (e.g., co-bonded or secondarily bonded)to charges 160 (e.g., second base-charge portion 144 of base charge 124)to form the part of second stiffener portion 106 and to charges 160(e.g., transition initial-charge portion 152 of initial charge 148 andtransition subsequent-charge-A portion of subsequent charge A) to formthe part of transition stiffener portion 110.

Referring generally to FIGS. 1A, 1B and 2-5 and particularly to, e.g.,FIGS. 9-11, thicknesses T of transition web-charge portion 182 of webcharge 178 and of transition opposing-web-charge portion 188 of opposingweb charge 184 progressively decrease from second stiffener portion 106to first stiffener portion 102. The preceding subject matter of thisparagraph characterizes example 18 of the present disclosure, whereinexample 18 also includes the subject matter according to example 17,above.

Thickness T of transition web-charge portion 182 of web charge 178 andof transition opposing-web-charge portion 188 of opposing web charge 184gradually decreasing from second stiffener portion 106 to firststiffener portion 102 gradually reduces transition cross-sectionalprofiles 112 from second stiffener portion 106 to first stiffenerportion 102.

The gradual reduction in thickness T of transition web-charge portion182 of web charge 178 and of transition opposing-web-charge portion 188of opposing web charge 184 may be created during the formation process(e.g., lay-up process) web charge 178 and opposing web charge 184.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5, 9-11, 21 and 22, transition web-charge portion 182 of web charge178 and transition opposing-web-charge portion 188 of opposing webcharge 184 taper from second stiffener portion 106 to first stiffenerportion 102. The preceding subject matter of this paragraphcharacterizes example 19 of the present disclosure, wherein example 19also includes the subject matter according to any one of examples 17 or18, above.

Transition web-charge portion 182 of web charge 178 and transitionopposing-web-charge portion 188 of opposing web charge 184 being taperedfrom second stiffener portion 106 to first stiffener portion 102smoothly blends transition cross-sectional profiles 112 from secondstiffener portion 106 to first stiffener portion 102.

The tapering of transition web-charge portion 182 of web charge 178 andtransition opposing-web-charge portion 188 of opposing web charge 184gradually reduces web 120 along transition stiffener portion 110 to apoint where web 120 (e.g., web charge 182 and opposing web charge 184)is effectively eliminated proximate (e.g., at or near) a transitionbetween transition stiffener portion 110 and first stiffener portion102.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-6, 9, 10 and 20-22, each of web charge 178 and opposing web charge 184is L-shaped. The preceding subject matter of this paragraphcharacterizes example 20 of the present disclosure, wherein example 20also includes the subject matter according to any one of examples 17-19,above.

L-shaped web charge 178 and opposing web charge 184 are used to form apart of T-shaped second cross-sectional profile 108 of second stiffenerportion 106.

As used herein, the term “L-shaped” refers to a shaped member having afirst (e.g., substantially vertical) portion and a second (e.g.,substantially horizontal) portion substantially perpendicularly coupledto a first end of the first portion. The second portion extendslaterally outward in one direction from the first end of the firstportion.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.7, each of web charge 178 and opposing web charge 184 is U-shaped. Thepreceding subject matter of this paragraph characterizes example 21 ofthe present disclosure, wherein example 21 also includes the subjectmatter according to any one of examples 17-19, above.

A U-shaped web charge 178 and opposing web charge 184 are used to form apart of the I-shaped second cross-sectional profile 108 of secondstiffener portion 106.

As used herein, the term “U-shaped” refers to a shaped member having afirst (e.g., substantially vertical) portion, a second (e.g.,substantially horizontal) portion perpendicularly coupled to a first endof the first portion, and a third (e.g., substantially horizontal)portion substantially perpendicularly coupled to a second end (oppositethe first end) of the first portion. The second portion extendslaterally outward in one direction from the first end of the firstportion. The third portion extends laterally outward in the same onedirection from the second end of the first portion.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.7, stiffener 100 further comprises cap charge 190, laminated ontoportions of web charge 178 and opposing web charge 184. Cap charge 190forms a part of second stiffener portion 106 and a part of transitionstiffener portion 110. The preceding subject matter of this paragraphcharacterizes example 22 of the present disclosure, wherein example 22also includes the subject matter according to example 21, above.

Cap charge 190 intercouples web charge 178 and opposing web charge 184and forms a part of the I-shaped second cross-sectional profile 108 ofsecond stiffener portion 106. Cap charge 190 further enables secondstiffener portion 106 and transition stiffener portion 110 to suitablyreact to bending loads primarily due to compression loading.

As one example, cap charge 190 is stacked on and laminated to the thirdportions of the U-shaped web charge 178 and opposing web charge 184.

Cap charge 190 may be formed from a composite material. For example, thecomposite material may include reinforcing fibers and resins. As oneexample, cap charge 190 may be a carbon fiber composite. Cap charge 190may be cured (e.g., co-cured) or bonded (e.g., co-bonded or secondarilybonded) to web 120 (e.g., web charge 178 and opposing web charge 184) toform the part of second stiffener portion 106 and the part of transitionstiffener portion 110.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-7, 9, 10 and 19-22, stiffener 100 further comprises filler charge 192between web charge 178 and opposing web charge 184. Filler charge 192comprises second filler-charge portion 194 and transition filler-chargeportion 196. A part of second stiffener portion 106 is formed by secondfiller-charge portion 194. A part of transition stiffener portion 110 isformed by transition filler-charge portion 196. The preceding subjectmatter of this paragraph characterizes example 23 of the presentdisclosure, wherein example 23 also includes the subject matteraccording to any one of examples 17-22, above.

Filler charge 192 enhances the load-carrying capabilities of stiffener100.

Filler charge 192 fills an open space between web charge 178 andopposing web charge 184. As one example, the open space between webcharge 178 and opposing web charge 184 is formed by the radius orangular transition between the first portions and the second portions ofthe L-shaped or U-shaped web charge 178 and opposing web charge 184.Filler charge 192 may be formed or cut as required to fill the openspace (e.g., the radius) between web charge 178 and opposing web charge184.

A cross-sectional dimension of second filler-charge portion 194 offiller charge 192 may be along second base-charge portion 144 of basecharge 124, for example, to form the part of second stiffener portion106. A cross-sectional dimension of transition filler-charge portion 196of filler charge 194 may gradually decrease along transitioninitial-charge portion 152 of initial charge 148 and transitionsubsequent-charge-A portion of subsequent charge A, for example, to formthe part of transition stiffener portion 110.

Filler charge 192 may be formed from a composite material. For example,the composite material may include reinforcing fibers or a woven fabricand resins. As one example, filler charge 192 may be a carbon fibercomposite. Filler charge 192 may be cured (e.g., co-cured) or bonded(e.g., co-bonded or secondarily bonded) to web 120 (e.g., web charge 178and opposing web charge 184), second base-charge portion 144 of basecharge 124, and transition initial-charge portion 152 of initial charge148 and transition subsequent-charge-A portion of subsequent charge A.

Referring to FIG. 7, as one example, stiffener 100 also includes anotherfiller charge 193 between web charge 178, opposing web charge 184, andcap charge 190. Filler charge 193 may be substantially the same asfiller charge 192. Filler charge 193 fills an open space between webcharge 178 and opposing web charge 184. As one example, the open spacebetween web charge 178 and opposing web charge 184 is formed by theradius or angular transition between the second portions and the thirdportions of the U-shaped web charge 178 and opposing web charge 184.Filler charge 192 may be formed or cut as required to fill the openspace (e.g., the radius) between web charge 178 and opposing web charge184.

When used in the construction of wing 206 of aircraft 208 (e.g., FIG.24), filler charge 192 of stiffener 100 may also be known as a radiusfiller or noodle.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.15, stiffener 100 further comprises subsequent charge B, laminated ontosubsequent charge A. Subsequent charge B comprises firstsubsequent-charge-B portion, forming a part of first stiffener portion102, and transition subsequent-charge-B portion, forming a part oftransition stiffener portion 110. First subsequent-charge-B portion ofsubsequent charge B is shaped identically to first subsequent-charge-Aportion of subsequent charge A. Transition subsequent-charge-B portionof subsequent charge B is smaller than transition subsequent-charge-Aportion of subsequent charge A and is shaped identically to a portion oftransition subsequent-charge-A portion. The preceding subject matter ofthis paragraph characterizes example 24 of the present disclosure,wherein example 24 also includes the subject matter according to any oneof examples 14-23, above.

Subsequent charge B being stacked and laminated onto subsequent charge Afurther increases combined height H1 (FIGS. 8-11) of charges 160,further partially defines first cross-sectional profile 104 of firststiffener portion 102 and transition cross-sectional profiles 112 oftransition stiffener portion 110, and enhances the load-carryingcapabilities of stiffener 100.

As illustrated in FIG. 15, first subsequent-charge-B portion ofsubsequent charge B has a generally rectangular 2D shape. A maximumwidth of first subsequent-charge-B portion is smaller than the maximumwidth of first subsequent-charge-A portion. Transitionsubsequent-charge-B portion has a generally trapezoidal 2D shape. Amaximum width of transition subsequent-charge-B portion is smaller thanthe maximum width of transition subsequent-charge-A portion. A maximumlength of transition subsequent-charge-B portion is less than themaximum length of transition subsequent-charge-A portion.

As illustrated in FIGS. 18-21, when additional charges 160 (e.g.,subsequent charge B) are used to form the part of first stiffenerportion 102 and the part of transition stiffener portion 110, coverlayer 176 also covers subsequent charge B, web 120 is also stacked andlaminated onto transition subsequent-charge-B portion of subsequentcharge B, and filler charge 192 is positioned on transitionsubsequent-charge-B portion between web charge 178 and opposing webcharge 184.

As described above, transition subsequent-charge-B has a trapezoidalcross-sectional shape. The stack of transition base-charge portion 146of base charge 124, transition initial-charge portion 152 of initialcharge 148, transition subsequent-charge-A portion of subsequent chargeA, and transition subsequent-charge-B portion of subsequent charge B hasa trapezoidal cross-sectional shape. The stack of first base-chargeportion 142 of base charge 124, first initial-charge portion 150 ofinitial charge 148, first subsequent-charge-A portion of subsequentcharge A, and first subsequent-charge-B portion of subsequent charge Bhas a trapezoidal cross-sectional shape.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.16 and 17, stiffener 100 further comprises subsequent charges B throughN, sequentially laminated onto subsequent charge A. Subsequent charges Bthrough N respectively comprise first subsequent-charge-B-through-Nportions, forming a part of first stiffener portion 102, and transitionsubsequent-charge-B-through-N portions, forming a part of transitionstiffener portion 110. First subsequent-charge-B-through-N portions ofsubsequent charges B through N are shaped identically to firstsubsequent-charge-A portion of subsequent charge A. Transitionsubsequent-charge-B-through-N portions of subsequent charges B through Nare smaller than transition subsequent-charge-A portion of subsequentcharge A. Each one of transition subsequent-charge-B-through-N portionsof subsequent charges B through N is smaller than a preceding one oftransition subsequent-charge-B-through-N portions of subsequent chargesB through N. Each one of transition subsequent-charge-B-through-Nportions of subsequent charges B through N is shaped identically to aportion of transition subsequent-charge-A portion. The preceding subjectmatter of this paragraph characterizes example 25 of the presentdisclosure, wherein example 25 also includes the subject matteraccording to any one of examples 14-23, above.

Subsequent charges B through N being sequentially stacked and laminatedonto subsequent charge A further increases combined height H1 (FIGS.8-11) of charges 160, further partially defines first cross-sectionalprofile 104 of first stiffener portion 102 and transitioncross-sectional profiles 112 of transition stiffener portion 110, andenhances the load-carrying capabilities of stiffener 100.

As illustrated in FIG. 16, each one of firstsubsequent-charge-B-through-N portions of subsequent charges B through Nhas a generally rectangular 2D shape. A maximum width of each one offirst subsequent-charge-B-through-N portions is smaller than the maximumwidth of first subsequent-charge-A portion and a maximum width of apreceding one of first subsequent-charge-B-through-N portions. Each oneof transition subsequent-charge-B-through-N portions of subsequentcharges B through N has a generally trapezoidal 2D shape. A maximumwidth of each one of transition subsequent-charge-B-through-N portionsis smaller than the maximum width of transition subsequent-charge-A anda maximum width of a preceding one of firstsubsequent-charge-B-through-N portions. A maximum length of each one oftransition subsequent-charge-B-through-N portions is less than themaximum length of transition subsequent-charge-A portion and a maximumlength of a preceding one of first subsequent-charge-B-through-Nportions.

As illustrated in FIGS. 18-21, when additional charges 160 (e.g.,subsequent charges B through N) are used to form the part of firststiffener portion 102 and the part of transition stiffener portion 110,cover layer 176 also covers subsequent charges B through N, web 120 isalso stacked and laminated onto transition subsequent-charge-B-through-Nportions of subsequent charges B through N, and filler charge 192 ispositioned on transition subsequent-charge-B-through-N portions betweenweb charge 178 and opposing web charge 184.

As described above, each one of transition subsequent-charge-B-through-Nportions of subsequent charges B through N has a trapezoidalcross-sectional shape. The stack of transition base-charge portion 146of base charge 124, transition initial-charge portion 152 of initialcharge 148, transition subsequent-charge-A portion of subsequent chargeA, and transition subsequent-charge-B-through-N portions of subsequentcharges B through N has a trapezoidal cross-sectional shape. The stackof first base-charge portion 142 of base charge 124, firstinitial-charge portion 150 of initial charge 148, firstsubsequent-charge-A portion of subsequent charge A, and firstsubsequent-charge-B-through-N portions of subsequent charges B through Nhas a trapezoidal cross-sectional shape.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-11 and 22, structure 200 is disclosed. Structure 200 comprises skin202, comprising surface 204, and stiffener 100, coupled to surface 204of skin 202. Stiffener 100 comprises first stiffener portion 102, havingfirst cross-sectional profile 104 that is constant along first stiffenerportion 102. Stiffener 100 also comprises second stiffener portion 106,having second cross-sectional profile 108 that is constant along secondstiffener portion 106. Second cross-sectional profile 108 of secondstiffener portion 106 is different from first cross-sectional profile104 of first stiffener portion 102. Stiffener 100 further comprisestransition stiffener portion 110, tapering from second stiffener portion106 to first stiffener portion 102. The preceding subject matter of thisparagraph characterizes example 26 of the present disclosure.

Structure 200 having skin 202 stiffened by stiffener 100 providesdifferent structural characteristics, for example, size, shape and/orload bearing characteristics along a length of stiffener 100.

First stiffener portion 102 and second stiffener portion 106 enable asingle continuous stiffener 100 having different cross-sectionalprofiles and/or dimensions to stiffen structure 200, which providedifferent structural characteristics, for example, size, shape and/orload bearing characteristics.

Transition stiffener portion 110 effectively transfers a load betweenfirst stiffer portion 102 and second stiffener portion 106. Graduallyshifting (e.g., tapering) from first cross-sectional profile 104 offirst stiffener portion 102 to second cross-sectional profile 108 ofsecond stiffener portion 106 along transition stiffener portion 110provides a more effective load transfer as compared to abutting,splicing or otherwise coupling two different stiffeners each having adifferent cross-sectional profile.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.4, 5, and 8, first cross-sectional profile 104 of first stiffenerportion 102 is trapezoidally shaped. The preceding subject matter ofthis paragraph characterizes example 27 of the present disclosure,wherein example 27 also includes the subject matter according to example26, above.

A trapezoidally shaped first cross-sectional profile 104 of firststiffener portion 102 of stiffener 100 enables first stiffener portion102 and, thus, structure 200 to suitably react to bending loadsprimarily due to tension loading, while also providing a relativelyshort profile height.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.4-6, second cross-sectional profile 108 of second stiffener portion 106is T-shaped. The preceding subject matter of this paragraphcharacterizes example 28 of the present disclosure, wherein example 28also includes the subject matter according to any one of examples 26 or27, above.

A T-shaped second-cross sectional profile 108 of second stiffenerportion 106 of stiffener 100 enables second stiffener portion 106, and,thus, structure 200 to suitably react to bending loads primarily due tocompression loading, while also providing a relatively tall profileheight.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.7, second cross-sectional profile 108 of second stiffener portion 106 isI-shaped. The preceding subject matter of this paragraph characterizesexample 29 of the present disclosure, wherein example 29 also includesthe subject matter according to any one of examples 26 or 27, above.

I-shaped second cross-sectional profile 108 of second stiffener portion106 of stiffener 100 enables second stiffener portion 106 and, thus,structure 200 to suitably react to bending loads primarily due tocompression loading, while also providing a relatively tall profileheight.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 9-11, transition stiffener portion 110 comprises transitioncross-sectional profiles 112. Transitional cross-sectional profiles 112of transition stiffener portion 110 are different from firstcross-sectional profile 104 of first stiffener portion 102 and secondcross-sectional profile 108 of second stiffener portion 106. Thepreceding subject matter of this paragraph characterizes example 30 ofthe present disclosure, wherein example 30 also includes the subjectmatter according to any one of examples 26-29, above.

Transition cross-sectional profiles 112 of transition stiffener portion110 gradually shifting (e.g., transitioning) from first cross-sectionalprofile 104 of first stiffener portion 102 to second cross-sectionalprofile 108 of second stiffener portion 106 to provides effective loadtransfer between first stiffener portion 102 and second stiffenerportion 106 through transition stiffener portion 110 and along skin 202of structure 200.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 9-11, all of transitional cross-sectional profiles 112 oftransition stiffener portion 110 are different. The preceding subjectmatter of this paragraph characterizes example 31 of the presentdisclosure, wherein example 31 also includes the subject matteraccording to example 30, above.

All of transition cross-sectional profiles 112 of transition stiffenerportion 110 being different provide a consistent and continualtransition (e.g., ramp rate) between first cross-sectional profile 104of first stiffener portion 102 and second cross-sectional profile 108 ofsecond stiffener portion 106 (e.g., from second cross-sectional profile108 of second stiffener portion 106 to first cross-sectional profile 104of first stiffener portion 102 or from first cross-sectional profile 104of first stiffener portion 102 to second cross-sectional profile 108 ofsecond stiffener portion 106).

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 9-11, transition cross-sectional profiles 112 smoothlytransition from second cross-sectional profile 108 of second stiffenerportion 106 to first cross-sectional profile 104 of first stiffenerportion 102. The preceding subject matter of this paragraphcharacterizes example 32 of the present disclosure, wherein example 32also includes the subject matter according to example 31, above.

A smooth transition between first cross-sectional profile 104 and secondcross-sectional profile 108 along transition cross-sectional profiles112 gradually changes the centroid of stiffener 100 and reduces thepotential of stiffener 100 pulling off of surface 204 of skin 202.

Abrupt changes to the centroid of stiffener 100 may increase thepotential of stiffener 100 pulling away from surface 204 of skin 202.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.6-11 and 13-22, stiffener 100 further comprises charges 160 laminatedtogether to form first stiffener portion 102, a part of second stiffenerportion 106, and a part of transition stiffener portion 110. Thepreceding subject matter of this paragraph characterizes example 33 ofthe present disclosure, wherein example 33 also includes the subjectmatter according to any one of examples 26-32, above.

Charges 160 that are stacked and laminated together form an integral,continuous part of stiffener 100 capable of effectively transferringloads between first stiffener portion 102 and second stiffener portion106 along transition stiffener portion 110.

Referring, e.g., to FIGS. 1A and 1B, stiffener 100 further comprisesprepreg composite plies 126 laminated together to form each one ofcharges 160. Prepreg composite plies 126 comprise reinforcement fibers240. Reinforcement fibers 240 of approximately fifty percent of prepregcomposite plies 126 are parallel to a primary load direction ofstiffener 100. Reinforcement fibers 240 of approximately forty percentof prepreg composite plies 126 are at forty-five degrees to primary loaddirection of stiffener 100. Reinforcement fibers 240 of approximatelyten percent of prepreg composite plies 126 are perpendicular to primaryload direction of stiffener 100. The preceding subject matter of thisparagraph characterizes example 34 of the present disclosure, whereinexample 34 also includes the subject matter according to example 33,above.

Varying and/or alternating the orientation of reinforcing fibers 240among prepreg composite plies 126, with respect to a longitudinal axisof each one of charges 160, at a plurality of different angles, such asapproximate angles of 0-degrees, −45-degrees, 90-degrees, and45-degrees, produces optimum mechanical properties (e.g., strengthand/or stiffness) in charges 160 and stiffener 100 formed from charges160.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-7, 9-11 and 22, stiffener 100 further comprises web 120, forming apart of second stiffener portion 106 and a part of transition stiffenerportion 110. Web 120 comprises base 122 and rib 168, perpendicular tobase 122. Base 122 of web 120 is parallel to charges 160. The precedingsubject matter of this paragraph characterizes example 35 of the presentdisclosure, wherein example 35 also includes the subject matteraccording to any one of examples 33 or 34, above.

Base 122 and rib 168 of web 120 enables second stiffener portion 106 andtransition stiffener portion 110 to suitably react to bending loads dueto compression and provides the majority of the height and a part of theshape of second cross-sectional profile 108 of second stiffener portion106 and transition cross-sectional profiles 112 of transition stiffenerportion.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 22, web 120 of stiffener 100 tapers from second stiffenerportion 106 to first stiffener portion 102. The preceding subject matterof this paragraph characterizes example 36 of the present disclosure,wherein example 36 also includes the subject matter according to example35, above.

Web 120 being tapered from second stiffener portion 106 to firststiffener portion 102 gradually reduces the height of transitioncross-sectional profiles 112 from second stiffener portion 106 to firststiffener portion 102 and effectively transfers loads between firststiffener portion 102 and second stiffener portion 106 along transitionstiffener portion 110.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.6-11, one of charges 160 has width W1 that gradually decreases alongtransition stiffener portion 110 from second stiffener portion 106 tofirst stiffener portion 102. Charges 160 have combined height H1 thatgradually increases along transition stiffener portion 110 from secondstiffener portion 106 to first stiffener portion 102. The precedingsubject matter of this paragraph characterizes example 37 of the presentdisclosure, wherein example 37 also includes the subject matteraccording to any one of examples 35 or 36, above.

Gradually decreasing width W1 of each one of charges 160 and graduallyincreasing combined height H1 of the stack of charges 160 alongtransition stiffener portion 110 provides for the smooth transition oftransition cross-sectional profiles 112 from second cross-sectionalprofile 108 to first cross-sectional profile 104 and enables effectiveload transfer between second stiffener portion 106 and first stiffenerportion 102 along transition stiffener portion 110.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.6-11, base 122 of web 120 has width W2 that progressively decreasesalong transition stiffener portion 110 from second stiffener portion 106to first stiffener portion 102. Rib 168 of web 120 has height H2 thatprogressively decreases along transition stiffener portion 110 fromsecond stiffener portion 106 to first stiffener portion 102. Thepreceding subject matter of this paragraph characterizes example 38 ofthe present disclosure, wherein example 38 also includes the subjectmatter according to example 37, above.

Progressively (e.g., gradually) decreasing width W2 of base 122 of web120 and progressively (e.g., gradually) decreasing height H2 of rib 168of web 120 provides for the smooth transition of transitioncross-sectional profiles 112 from second cross-sectional profile 108 tofirst cross-sectional profile 104 and enables effective load transferbetween second stiffener portion 106 and first stiffener portion 102along transition stiffener portion 110.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 12-14, stiffener 100 further comprises base charge 124,comprising first base-charge portion 142, forming a part of firststiffener portion 102, second base-charge portion 144, forming a part ofsecond stiffener portion 106, and transition base-charge portion 146,forming a part of transition stiffener portion 110. Transitionbase-charge portion 146 of base charge 124 tapers from secondbase-charge portion 144 to first base-charge portion 142. Stiffener alsocomprises initial charge 148, laminated onto base charge 124. Initialcharge 148 comprises first initial-charge portion 150, forming a part offirst stiffener portion 102, and transition initial-charge portion 152,forming a part of transition stiffener portion 110. First initial-chargeportion 150 of initial charge 148 is shaped identically to firstbase-charge portion 142 of base charge 124, and transitioninitial-charge portion 152 of initial charge 148 is shaped identicallyto at least a portion of transition base-charge portion 146 of basecharge 124. Stiffener 100 further comprises subsequent charge A,laminated onto initial charge 148. Subsequent charge A comprises firstsubsequent-charge-A portion, forming a part of first stiffener portion102, and transition subsequent-charge-A portion, forming a part oftransition stiffener portion 110. First subsequent-charge-A portion ofsubsequent charge A is shaped identically to first initial-chargeportion 150 of initial charge 148, and transition subsequent-charge-Aportion of subsequent charge A is smaller than transition initial-chargeportion 152 of initial charge 148 and is shaped identically to a portionof transition initial-charge portion 152. The preceding subject matterof this paragraph characterizes example 39 of the present disclosure,wherein example 39 also includes the subject matter according to any oneof examples 26-38, above.

A laminated stack of base charge 124, initial charge 148, and subsequentcharge A form an integral, continuous part of stiffener 100 capable ofeffectively reacting to loads (e.g., different bending loads) andtransferring loads between first stiffener portion 102 and secondstiffener portion 106 along transition stiffener portion 110 and alongskin 202.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 22, stiffener 100 further comprises web 120, forming a part ofsecond stiffener portion 106 and a part of transition stiffener portion110. The preceding subject matter of this paragraph characterizesexample 40 of the present disclosure, wherein example 40 also includesthe subject matter according to example 39, above.

Web 120 enables second stiffener portion 106 and transition stiffenerportion 110 and, thus, skin 202 to suitably react to bending loadsprimarily due to compression and provides the majority of the height ofsecond cross-sectional profile 108 of second stiffener portion 106 andtransition cross-sectional profiles 112 of transition stiffener portion.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.18-21, stiffener 100 further comprises cover layer 176 between web 120and subsequent charge A, initial charge 148, and base charge 124. Coverlayer 176 covers first stiffener portion 102, formed, at leastpartially, by first base-charge portion 142 of base charge 124, firstinitial-charge portion 150 of initial charge 148, and firstsubsequent-charge-A portion of subsequent charge A. Cover layer 176 alsocovers a part of transition stiffener portion 110, formed, at leastpartially, by transition base-charge portion 146 of base charge 124,transition initial-charge portion 152 of initial charge 148, andtransition subsequent-charge-A portion of subsequent charge A.Additionally, cover layer 176 covers a part of second stiffener portion106, formed, at least partially, by second base-charge portion 144 ofbase charge 124. The preceding subject matter of this paragraphcharacterizes example 41 of the present disclosure, wherein example 41also includes the subject matter according to example 40, above.

Covering (e.g., wrapping) base charge 124, initial charge 148 andsubsequent charge A with cover layer 176 further integrates base charge124, initial charge 148 and subsequent charge A (e.g., charges 160) intoa continuous part of stiffener 100 capable of reacting to bending loadsand transferring loads between first stiffener portion 102 and secondstiffener portion 106.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.18-21, cover layer 176 covers at least a portion of surface 204 of skin202. The preceding subject matter of this paragraph characterizesexample 42 of the present disclosure, wherein example 42 also includesthe subject matter according to example 41, above.

Covering (e.g., wrapping) base charge 124, initial charge 148 andsubsequent charge A (e.g., charges 160) and at least a portion ofsurface 204 of skin 202 with cover layer 176 further integrates basecharge 124, initial charge 148, subsequent charge A and skin 202 intointegral structure 200 capable of reacting to bending loads andtransferring loads between first stiffener portion 102 and secondstiffener portion 106 and along skin 202.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 20-22, web 120 of stiffener 100 comprises web charge 178 thatcomprises second web-charge portion 180, forming a part of secondstiffener portion 106, and transition web-charge portion 182, forming apart of transition stiffener portion 110. Web 120 of stiffener 100 alsocomprises opposing web charge 184, abutting a portion of web charge 178.Opposing web charge 184 comprises second opposing-web-charge portion186, forming a part of second stiffener portion 106, and transitionopposing-web-charge portion 188, forming a part of transition stiffenerportion 110. The preceding subject matter of this paragraphcharacterizes example 43 of the present disclosure, wherein example 43also includes the subject matter according to any one of examples 40-42,above.

Web charge 178 and opposing web charge 184 in combination enable secondstiffener portion 106 and transition stiffener portion 110 to suitablyreact to bending loads primarily due to compression and provides themajority of the height and a part of the shape of second cross-sectionalprofile 108 of second stiffener portion 106 and transitioncross-sectional profiles 112 of transition stiffener portion.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5 and 9-11, thicknesses T of transition web-charge portion 182 of webcharge 178 and of transition opposing-web-charge portion 188 of opposingweb charge 184 progressively decrease from second stiffener portion 106to first stiffener portion 102. The preceding subject matter of thisparagraph characterizes example 44 of the present disclosure, whereinexample 44 also includes the subject matter according to example 43,above.

Thickness T of transition web-charge portion 182 of web charge 178 andof transition opposing-web-charge portion 188 of opposing web charge 184gradually decreasing from second stiffener portion 106 to firststiffener portion 102 gradually reduces the transition cross-sectionalprofiles 112 from second stiffener portion 106 to first stiffenerportion 102.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-5, 9-11, 21 and 22, transition web-charge portion 182 of web charge178 and transition opposing-web-charge portion 188 of opposing webcharge 184 taper from second stiffener portion 106 to first stiffenerportion 102. The preceding subject matter of this paragraphcharacterizes example 45 of the present disclosure, wherein example 45also includes the subject matter according to any one of examples 43 or44, above.

Transition web-charge portion 182 of web charge 178 and transitionopposing-web-charge portion 188 of opposing web charge 184 being taperedfrom second stiffener portion 106 to first stiffener portion 102smoothly transitions the transition cross-sectional profiles 112 fromsecond stiffener portion 106 to first stiffener portion 102.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-6, 9, 10 and 20-22, each of web charge 178 and opposing web charge 184is L-shaped. The preceding subject matter of this paragraphcharacterizes example 46 of the present disclosure, wherein example 46also includes the subject matter according to any one of examples 43-45,above.

L-shaped web charge 178 and opposing web charge 184 are used to form apart of T-shaped second cross-sectional profile 108 of second stiffenerportion 106.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.7, each of web charge 178 and opposing web charge 184 is U-shaped. Thepreceding subject matter of this paragraph characterizes example 47 ofthe present disclosure, wherein example 47 also includes the subjectmatter according to any one of examples 43-45, above.

U-shaped web charge 178 and opposing web charge 184 are used to form apart of I-shaped second cross-sectional profile 108 of second stiffenerportion 106.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.7, stiffener 100 further comprises cap charge 190, laminated ontoportions of web charge 178, and opposing web charge 184. Cap charge 190forms a part of second stiffener portion 106 and a part of transitionstiffener portion 110. The preceding subject matter of this paragraphcharacterizes example 48 of the present disclosure, wherein example 48also includes the subject matter according to example 47, above.

Cap charge 190 intercouples web charge 178 and opposing web charge 184and forms a part of the I-shaped second cross-sectional profile 108 ofsecond stiffener portion 106. Cap charge 190 further enables secondstiffener portion 106 and transition stiffener portion 110 to suitablyreact to bending loads primarily due to compression loading.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-7, 9, 10 and 19-22, stiffener 100 further comprises filler charge 192between web charge 178 and opposing web charge 184. Filler charge 192comprises second filler-charge portion 194, forming a part of secondstiffener portion 106, and transition filler-charge portion 196, forminga part of transition stiffener portion 110. The preceding subject matterof this paragraph characterizes example 49 of the present disclosure,wherein example 49 also includes the subject matter according to any oneof examples 43-48, above.

Filler charge 192 enhances the load-carrying capabilities of stiffener100 and structure 200.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.15, stiffener 100 further comprises subsequent charge B, laminated ontosubsequent charge A. Subsequent charge B comprises firstsubsequent-charge-B portion, forming a part of first stiffener portion102, and transition subsequent-charge-B portion, forming a part oftransition stiffener portion 110. First subsequent-charge-B portion ofsubsequent charge B is shaped identically to first subsequent-charge-Aportion of subsequent charge A. Transition subsequent-charge-B portionof subsequent charge B is smaller than transition subsequent-charge-Aportion of subsequent charge A and is shaped identically to a portion oftransition subsequent-charge-A portion. The preceding subject matter ofthis paragraph characterizes example 50 of the present disclosure,wherein example 50 also includes the subject matter according to any oneof examples 39-49, above.

Subsequent charge B being stacked and laminated onto subsequent charge Afurther increases combined height H1 (FIGS. 8-11) of charges 160,further partially defines first cross-sectional profile 104 of firststiffener portion 102 and transition cross-sectional profiles 112 oftransition stiffener portion 110, and enhances the load-carryingcapabilities of stiffener 100 and, thus, structure 200.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.16 and 17, stiffener 100 further comprises subsequent charges B throughN, sequentially laminated onto subsequent charge A. Subsequent charges Bthrough N, respectively, comprise first subsequent-charge-B-through-Nportions, forming a part of first stiffener portion 102, and transitionsubsequent-charge-B-through-N portions, forming a part of transitionstiffener portion 110. First subsequent-charge-B-through-N portions ofsubsequent charges B through N are shaped identically to firstsubsequent-charge-A portion of subsequent charge A. Transitionsubsequent-charge-B-through-N portions of subsequent charges B through Nare smaller than transition subsequent-charge-A portion of subsequentcharge A. Each one of transition subsequent-charge-B-through-N portionsof subsequent charges B through N is smaller than a preceding one oftransition subsequent-charge-B-through-N portions of subsequent chargesB through N. Each one of is transition subsequent-charge-B-through-Nportions of subsequent charges B through N is shaped identically to aportion of transition subsequent-charge-A portion. The preceding subjectmatter of this paragraph characterizes example 51 of the presentdisclosure, wherein example 51 also includes the subject matteraccording to any one of examples 39-49, above.

Subsequent charges B through N being sequentially stacked and laminatedonto subsequent charge A further increases combined height H1 (FIGS.8-11) of charges 160, further partially defines first cross-sectionalprofile 104 of first stiffener portion 102 and transitioncross-sectional profiles 112 of transition stiffener portion 110, andenhances the load-carrying capabilities of stiffener 100 and, thus,structure 200.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.23, structure 200 also comprises first brace 210, coupled to firststiffener portion 102 of stiffener 100. Structure 200 further comprisessecond brace 212, coupled to second stiffener portion 106 of stiffener100. The preceding subject matter of this paragraph characterizesexample 52 of the present disclosure, wherein example 52 also includesthe subject matter according to any one of examples 26-51, above.

First brace 210 and second brace 212 couples stiffener 100 and, thus,skin 202 to another component, for example, another component ofstructure 200 positioned opposite skin 202 and distribute loads.

First brace 210 is configured (e.g., suitably shaped) to be coupled tofirst cross-sectional profile 104 of first stiffener portion 102. Secondbrace 212 is configured (e.g., suitably shaped) to be coupled to secondcross-sectional profile 108 of second stiffener portion 106.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.23, transition stiffener portion 110 is positioned between first brace210 and second brace 212. The preceding subject matter of this paragraphcharacterizes example 53 of the present disclosure, wherein example 53also includes the subject matter according to example 52, above.

Positioning transition stiffener portion 110 between first brace 210 andsecond brace 212 enables effective load transfer between first stiffenerportion 102 and second stiffener portion 106 (e.g., from secondstiffener portion 106 to first stiffener portion 102) and distributionof the load to first brace 210 and second brace 212.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.23, skin 202 is upper skin 216. Stiffener 100 is upper stiffener 220.Structure 200 further comprises lower skin 218 opposite upper skin 216and lower stiffener 222 coupled to lower skin 218. First brace 210 andsecond brace 212 are coupled to upper stiffener 220 and lower stiffener222. The preceding subject matter of this paragraph characterizesexample 54 of the present disclosure, wherein example 54 also includesthe subject matter according to any one of examples 52 or 53, above.

Upper skin 216 stiffened by upper stiffener 220 and lower skin 218stiffened by lower stiffener 222 form structure 200, such as a boxstructure, with upper skin 216 and lower skin 222 being spaced apart andintercoupled by first brace 210 and second brace 212.

Upper stiffener 220 including second stiffener portion 106 having a highprofile (e.g., a tall second cross-sectional profile 108) and firststiffener portion 102 having a low profile (e.g., a short firstcross-sectional profile 104) enables a distance between upper skin 216and lower skin 218 to be reduced, at least along first stiffener portion102 of upper stiffener 220, resulting in structure 200 having a reducedthickness and/or an increase in the available clearance between upperskin 216 (and upper stiffener 220) and lower skin 218 (and lowerstiffener 222).

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.23 and 24, structure 200 is wing 206 of aircraft 208. Upper stiffener220 is upper stringer 224 of wing 206. Lower stiffener 222 is lowerstringer 226 of wing 206. First brace 210 and second brace 212 are eachrib 214 of wing 206. The preceding subject matter of this paragraphcharacterizes example 55 of the present disclosure, wherein example 55also includes the subject matter according to example 54, above.

Upper stringer 224 having a low profile portion (e.g., first stiffenerportion 102 having first cross-sectional profile 104) enables a decreasein the thickness of wing 206, at least along a portion of wing 206stiffened by first stiffener portion 102 of upper stringer 224 (e.g.,outboard portion 242 of wing 206).

As one example, distance D (FIG. 23) between upper skin 216 having upperstringer 224 and lower skin 218 having lower stringer 226 may be reducedalong a length of wing 206 associated with first stiffener portion 102having first cross-sectional profile 104. Because first cross-sectionalprofile 104 of first stiffener portion 102 of upper stringer 216 isrelatively short (e.g., compared to a relatively tall secondcross-sectional profile 108 of second stringer portion 106), distance Dcan be decreased, for example, about outboard portion 242 of wing 206,while allowing a sufficient clearance between upper skin 216 and lowerskin 218.

Ribs 214 provide shape and support to wing 206 (e.g., the wingboxstructure). Ribs 214 distribute loads from and between upper stringer224 and lower stringer 226. A distance between ribs 214 may define a ribbay (not explicitly illustrated). Transition stiffener portion 110 ofupper stiffener 224 may be positioned within the rib bay (e.g., mayextend between adjacent ribs 214).

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.23, lower stiffener 222 has a constant cross-sectional profile. Thepreceding subject matter of this paragraph characterizes example 56 ofthe present disclosure, wherein example 56 also includes the subjectmatter according to example 55, above.

A constant cross-sectional profile of lower stiffener 222 enables lowerstiffener 222 to suitably react to certain types of loads (e.g., bendingloads primarily due to tension loading).

The cross-sectional profile of lower stiffener 222 may have any suitableshape depending upon the particular structural application of lowerstiffener 222, for example, when used to construct structure 200. As oneexample, the cross-sectional profile of lower stiffener 222 may bedesigned to react to bending loads primarily due to tension.

Lower stiffener 222 may have a different cross-sectional profile than across-sectional profile of at least part of upper stiffener 220. As oneexample, the cross-sectional profile of lower stiffener 222 may be thesame as first cross-sectional profile 104 of first stiffener portion 102of upper stiffener 220 and different than second cross-sectional profile108 of second stiffener portion 106 of upper stiffener 220.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.23, cross-sectional profile of lower stiffener 222 is trapezoidal. Thepreceding subject matter of this paragraph characterizes example 57 ofthe present disclosure, wherein example 57 also includes the subjectmatter according to any one of examples 55 or 56, above.

A trapezoidally shaped cross-sectional profile of lower stiffener 222enables lower stiffener 222 to suitably react to bending loads primarilydue to tension loading, while also providing a relatively short profileheight.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.24, wing 206 comprises a length, first end 228 coupled to fuselage 232of aircraft 208, and second end 230 opposite first end 228. Upperstiffener 220 extends continuously from first end 228 of wing 206 tosecond end 230 of wing 206. The preceding subject matter of thisparagraph characterizes example 58 of the present disclosure, whereinexample 58 also includes the subject matter according to any one ofexamples 55-57, above.

Second stiffener portion 106 having second cross-sectional profile 108of upper stiffener 220 (e.g., upper stringer 224) extending continuouslyfrom first end 228 to second end 230 of wing 206 enables wing 206 toreact to bending loads primarily due to compression.

As one example, at least a portion of the length of wing 206 thatexperiences bending loads primary from compression is stiffened bysecond stiffener portion 106 of upper stiffener 220. A remaining portionof the length of wing 206 (e.g., outboard portion 242) is stiffened byfirst stiffener portion 102 of upper stiffener 220 since bending loadsprimarily from compression imposed on wing 206 are less farther fromfuselage 232.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.24, transition portion 110 of upper stiffener 220 is located at leasttwenty-five percent of length of wing 206 away from second end 230 ofwing 206. The preceding subject matter of this paragraph characterizesexample 59 of the present disclosure, wherein example 59 also includesthe subject matter according to example 58, above.

Transition portion 110 of upper stiffener 220 being located at leasttwenty-five percent of length of wing 206 away from second end 230 ofwing 206 defines the length of first stiffener portion 102 of upperstiffener 220 relative to second stiffener portion 106 of upperstiffener 220 and enables a reduction in thickness of an outermosttwenty-five percent of wing 206.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIG.24, transition portion 110 of upper stiffener 220 is located at leastfifty percent of length of wing 206 away from first end 228 of wing 206.The preceding subject matter of this paragraph characterizes example 60of the present disclosure, wherein example 60 also includes the subjectmatter according to example 59, above.

Transition portion 110 of upper stiffener 220 being located at leastfifty percent of length of wing 206 away from second end 230 of wing 206defines the length of first stiffener portion 102 of upper stiffener 220relative to second stiffener portion 106 of upper stiffener 220 andenables a reduction in thickness of an outermost fifty percent of wing206.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-11 and 22, stiffener 100 is co-cured with skin 202. The precedingsubject matter of this paragraph characterizes example 61 of the presentdisclosure, wherein example 61 also includes the subject matteraccording to any one of examples 26-60, above.

Co-curing stiffener 100 and skin 202 bonds stiffener 100 and skin 202 atleast partially defines the load bearing and load transferringcharacteristics of structure 200. In the co-curing process, bothstiffener 100 and skin 202 are formed from an uncured compositematerial. All resins of the uncured composite materials of bothstiffener 100 and skin 202 are simultaneously cured during the sameprocess to bond stiffener 100 to skin 202.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-11 and 22, stiffener 100 is co-bonded to skin 202. The precedingsubject matter of this paragraph characterizes example 62 of the presentdisclosure, wherein example 62 also includes the subject matteraccording to any one of examples 26-60, above.

Co-bonding stiffener 100 and skin 202 bonds stiffener 100 and skin 202at least partially defines the load bearing and load transferringcharacteristics of structure 200. In the co-bonding process, one ofstiffener 100 and skin 202 is formed from an uncured composite materialand one of stiffener 100 and skin 202 is formed from a cured compositematerial. Resins of the uncured composite material are cured during theprocess to bond stiffener 100 to skin 202.

Referring generally to FIGS. 1A and 1B and particularly to, e.g., FIGS.2-11 and 22, stiffener 100 is secondarily bonded to skin 202. Thepreceding subject matter of this paragraph characterizes example 63 ofthe present disclosure, wherein example 63 also includes the subjectmatter according to any one of examples 26-60, above.

Secondarily bonding stiffener 100 and skin 202 bonds stiffener 100 andskin 202 at least partially defines the load bearing and loadtransferring characteristics of structure 200. In the secondary bondingprocess, both stiffener 100 and skin 202 are formed from a cured (e.g.,pre-cured) composite material. An adhesive is applied between stiffener100 and skin 202 and is cured during the same process to bond stiffener100 to skin 202.

Referring generally to FIGS. 1A, 1B and 2-14 and particularly to, e.g.,FIG. 25A, method 300 of making stiffener 100 is disclosed. Method 300comprises laying up base charge 124 to form a part of first stiffenerportion 102 of stiffener 100 from first base-charge portion 142 of basecharge 124, to form a part of second stiffener portion 106 of stiffener100 from second base-charge portion 144 of base charge 124, and to forma part of transition stiffener portion 110 of stiffener 100 fromtransition base-charge portion 146 of base charge 124 (Block 302).Transition base-charge portion 146 tapers from second base-chargeportion 144 to first base-charge portion 142 (Block 304). Method 300also comprises laminating initial charge 148 onto base charge 124 toform a part of first stiffener portion 102 of stiffener 100 from firstinitial-charge portion 150 of initial charge 148 and to form a part oftransition stiffener portion 110 of stiffener 100 from transitioninitial-charge portion 152 of initial charge 148 (Block 306). Firstinitial-charge portion 150 of initial charge 148 is shaped identicallyto first base-charge portion 142 of base charge 124 (Block 308).Transition initial-charge portion 152 of initial charge 148 is shapedidentically to at least a portion of transition base-charge portion 146of base charge 124 (Block 310). Method 300 also comprises laminatingsubsequent charge A onto initial charge 148 to form a part of firststiffener portion 102 of stiffener 100 from first subsequent-charge-Aportion of subsequent charge A and to form a part of transitionstiffener portion 110 of stiffener 100 from transitionsubsequent-charge-A portion of subsequent charge A (Block 312). Firstsubsequent-charge-A portion of subsequent charge A is shaped identicallyto first initial-charge portion 150 of initial charge 148 (Block 314).Transition subsequent-charge-A portion of subsequent charge A is smallerthan transition initial-charge portion 152 of initial charge 148 and isshaped identically to a portion of transition initial-charge portion 152(Block 316). The preceding subject matter of this paragraphcharacterizes example 64 of the present disclosure.

Laminating a successive stack of base charge 124, initial charge 148 andsubsequent charge A thereby forms integral and continuous portions ofpart of stiffener 100 (e.g., first stiffener portion 102, part oftransition stiffener portion 110, and part of second stiffener portion106) capable of effectively reacting to loads (e.g., different bendingloads) and transferring loads between first stiffener portion 102 andthe part of second stiffener portion 106 along the part of transitionstiffener portion 110.

Referring generally to FIGS. 1A, 1B and 15 and particularly to, e.g.,FIG. 25A, method 300 also comprises laminating subsequent charge B ontosubsequent charge A to form a part of first stiffener portion 102 ofstiffener 100 from first subsequent-charge-B portion of subsequentcharge B and to form a part of transition stiffener portion 110 ofstiffener 100 from transition subsequent-charge-B portion of subsequentcharge B (Block 318). First subsequent-charge-B portion of subsequentcharge B is shaped identically to first subsequent-charge-A portion ofsubsequent charge A (Block 320). Transition subsequent-charge-B portionof subsequent charge B is smaller than transition subsequent-charge-Aportion of subsequent charge A and is shaped identically to a portion oftransition subsequent-charge-A portion (Block 322). The precedingsubject matter of this paragraph characterizes example 65 of the presentdisclosure, wherein example 65 also includes the subject matteraccording to example 64, above.

Laminating subsequent charge B stacked onto subsequent charge A furtherincreases combined height H1 (FIGS. 8-11) of the part of first stiffenerportion 102 and transition stiffener portion 110, further partiallydefines first cross-sectional profile 104 of first stiffener portion 102and transition cross-sectional profiles 112 of transition stiffenerportion 110, and enhances the load-carrying capabilities of stiffener100.

Referring generally to FIGS. 1A, 1B, 16 and 17 and particularly to,e.g., FIG. 25B, method 300 further comprises providing a smoothtransition among transition initial-charge portion 152 of initial charge148, transition subsequent-charge-A portion of subsequent charge A, andtransition subsequent-charge-B portion of subsequent charge B (Block324). The preceding subject matter of this paragraph characterizesexample 66 of the present disclosure, wherein example 66 also includesthe subject matter according to example 65, above.

Providing a smooth transition among transition initial-charge portion152 of initial charge 148, transition subsequent-charge-A portion ofsubsequent charge A, and transition subsequent-charge-B portion ofsubsequent charge B gradually changes the centroid of the part ofstiffener 100 and reduces the potential of transition initial-chargeportion 152 of initial charge 148, transition subsequent-charge-Aportion of subsequent charge A, and transition subsequent-charge-Bportion of subsequent charge B pulling away from each other, forexample, under a bending load.

Referring generally to FIGS. 1A, 1B, 16 and 17 and particularly to,e.g., FIG. 25B, providing the smooth transition among transitioninitial-charge portion 152 of initial charge 148, transitionsubsequent-charge-A portion of subsequent charge A, and transitionsubsequent-charge-B portion of subsequent charge B (Block 324) comprisesremoving end portions of transition initial-charge portion 152,transition subsequent-charge-A portion, and transitionsubsequent-charge-B portion (Block 326). The preceding subject matter ofthis paragraph characterizes example 67 of the present disclosure,wherein example 67 also includes the subject matter according to example66, above.

Removing end portions of transition initial-charge portion 152,transition subsequent-charge-A portion, and transitionsubsequent-charge-B portion, for example, at a predetermined cuttingangle (e.g., similar to the ramp rate of the increase in combined heightH1 of charges 160), provides a smooth surface along the part oftransition stiffener portion 110.

As one example, cover layer 176, filler charge 192, and/or web 120 maybe stacked on and laminated to the smooth surface of transitionstiffener portion 110.

As one example, ends portions (illustrated but not explicitlyidentified) of transition initial-charge portion 152, transitionsubsequent-charge-A portion, and transition subsequent-charge-B portionmay be removed (e.g., cut off) by using an ultrasonic knife (notexplicitly illustrated), for example, under computer control. As oneexample, ends portions of transition initial-charge portion 152,transition subsequent-charge-A portion, and transitionsubsequent-charge-B portion may be cut away at an angle.

Referring generally to FIGS. 1A, 1B and 18 and particularly to, e.g.,FIG. 25B, method 300 also comprises covering, with cover layer 176,first stiffener portion 102, formed, at least partially, by firstbase-charge portion 142 of base charge 124, first initial-charge portion150 of initial charge 148, and first subsequent-charge-A portion ofsubsequent charge A (Block 328). Method 300 also comprises covering,with cover layer 176, a part of transition stiffener portion 110 formed,at least partially, by transition base-charge portion 146 of base charge124, transition initial-charge portion 152 of initial charge 148, andtransition subsequent-charge-A portion of subsequent charge A (Block330). Additionally, method 300 comprises covering, with cover layer 176,a part of second stiffener portion 106, formed, at least partially, bysecond base-charge portion 144 of base charge 124 (Block 332). Thepreceding subject matter of this paragraph characterizes example 68 ofthe present disclosure, wherein example 68 also includes the subjectmatter according to any one of examples 65-67, above.

Covering (e.g., wrapping) first stiffener portion 102, the part oftransition stiffener portion 110, and the part of second stiffenerportion 106 with cover layer 176 further integrates first base-chargeportion 142 of base charge 124, first initial-charge portion 150 ofinitial charge 148, first subsequent-charge-A portion of subsequentcharge A, transition base-charge portion 146 of base charge 124,transition initial-charge portion 152 of initial charge 148, transitionsubsequent-charge-A portion of subsequent charge A, and secondbase-charge portion 144 of base charge 124 into a continuous part ofstiffener 100 capable of reacting to bending loads and transferringloads between first stiffener portion 102 and second stiffener portion106 along transition stiffener portion 110.

Referring generally to FIGS. 1A, 1B and 22 and particularly to, e.g.,FIG. 25B, method 300 further comprises adding web 120 that forms a partof second stiffener portion 106 and a part of transition stiffenerportion 110 (Block 334). The preceding subject matter of this paragraphcharacterizes example 69 of the present disclosure, wherein example 69also includes the subject matter according to any one of examples 64-68,above.

Providing web 120 enables second stiffener portion 106 and transitionstiffener portion 110 to suitably react to bending loads primarily dueto compression.

Referring generally to FIGS. 1A, 1B, 20 and 21 and particularly to,e.g., FIG. 25B, adding web 120 (Block 334) comprises forming a part ofsecond stiffener portion 106 from second web-charge portion 180 of webcharge 178 (Block 336). Adding web 120 also comprises forming a part oftransition stiffener portion 110 from transition web-charge portion 182of web charge 178 (Block 338). Adding web 102 further comprises abuttingopposing web charge 184 with web charge 178 (Block 340), forming a partof second stiffener portion 106 from second opposing-web-charge portion186 of opposing web charge 184 (Block 342), and forming a part oftransition stiffener portion 110 from transition opposing-web-chargeportion 188 of opposing web charge 184 (Block 344). The precedingsubject matter of this paragraph characterizes example 70 of the presentdisclosure, wherein example 70 also includes the subject matteraccording to example 69, above.

In combination, providing web charge 178 and opposing web charge 184enable second stiffener portion 106 and transition stiffener portion 110to suitably react to bending loads primarily due to compression andprovides the majority of the height and a part of the shape of secondcross-sectional profile 108 of second stiffener portion 106 andtransition cross-sectional profiles 112 of transition stiffener portion.

Referring generally to FIGS. 1A, 1B and 19-21 and particularly to, e.g.,FIG. 25B, method 300 further comprises placing filler charge 192 betweenweb charge 178 and opposing web charge 184 to form a part of secondstiffener portion 106 from second filler-charge portion 194 of fillercharge 192 and to form a part of transition stiffener portion 110 fromtransition filler-charge portion 196 of filler charge 192 (Block 346).The preceding subject matter of this paragraph characterizes example 71of the present disclosure, wherein example 71 also includes the subjectmatter according to example 70, above.

Providing filler charge 192 between web charge 178 and opposing webcharge 184 fills an open space between web charge 178 and opposing webcharge 184 enhances the load-carrying capabilities of stiffener 100.

Referring generally to FIGS. 1A, 1B and 22 and particularly to, e.g.,FIG. 25B, method 300 further comprises trimming transition web-chargeportion 182 of web charge 178 and transition opposing-web-charge portion188 of opposing web charge 184 such that transition web-charge portion182 of web charge 178 and transition opposing-web-charge portion 188 ofopposing web charge 184 taper from second stiffener portion 106 to firststiffener portion 102 (Block 348). The preceding subject matter of thisparagraph characterizes example 72 of the present disclosure, whereinexample 72 also includes the subject matter according to any one ofexamples 70 or 71, above.

Trimming transition web-charge portion 182 of web charge 178 andtransition opposing-web-charge portion 188 of opposing web charge 184 totaper transition web-charge portion 182 and transitionopposing-web-charge portion 188 from second stiffener portion 106 tofirst stiffener portion 102 provides smooth transition between secondstiffener portion 106 to first stiffener portion 102 along transitionstiffener portion 110 and gradually changes the centroid of stiffener100.

As one example, transition web-charge portion 182 of web charge 178 andtransition opposing-web-charge portion 188 of opposing web charge 184may be performed (e.g., cut off) by using an ultrasonic knife (notexplicitly illustrated), for example, under computer control. As oneexample, ends portions of transition initial-charge portion 152,transition subsequent-charge-A portion, and transitionsubsequent-charge-B portion may be cut away at an angle.

Examples of the present disclosure may be described in the context ofaircraft manufacturing and service method 1100 as shown in FIG. 26 andaircraft 1102 as shown in FIG. 27. During pre-production, illustrativemethod 1100 may include specification and design (block 1104) ofaircraft 1102 and material procurement (block 1106). During production,component and subassembly manufacturing (block 1108) and systemintegration (block 1110) of aircraft 1102 may take place. Thereafter,aircraft 1102 may go through certification and delivery (block 1112) tobe placed in service (block 1114). While in service, aircraft 1102 maybe scheduled for routine maintenance and service (block 1116). Routinemaintenance and service may include modification, reconfiguration,refurbishment, etc. of one or more systems of aircraft 1102.

Each of the processes of illustrative method 1100 may be performed orcarried out by a system integrator, a third party, and/or an operator(e.g., a customer). For the purposes of this description, a systemintegrator may include, without limitation, any number of aircraftmanufacturers and major-system subcontractors; a third party mayinclude, without limitation, any number of vendors, subcontractors, andsuppliers; and an operator may be an airline, leasing company, militaryentity, service organization, and so on.

As shown in FIG. 27, aircraft 1102 produced by illustrative method 1100may include airframe 1118 with a plurality of high-level systems 1120and interior 1122. Examples of high-level systems 1120 include one ormore of propulsion system 1124, electrical system 1126, hydraulic system1128, and environmental system 1130. Any number of other systems may beincluded. Although an aerospace example is shown, the principlesdisclosed herein may be applied to other industries, such as theautomotive industry. Accordingly, in addition to aircraft 1102, theprinciples disclosed herein may apply to other vehicles, e.g., landvehicles, marine vehicles, space vehicles, etc.

Apparatus(es) and method(s) shown or described herein may be employedduring any one or more of the stages of the manufacturing and servicemethod 1100. For example, components or subassemblies corresponding tocomponent and subassembly manufacturing (block 1108) may be fabricatedor manufactured in a manner similar to components or subassembliesproduced while aircraft 1102 is in service (block 1114). Also, one ormore examples of the apparatus(es), method(s), or combination thereofmay be utilized during production stages 1108 and 1110, for example, bysubstantially expediting assembly of or reducing the cost of aircraft1102. Similarly, one or more examples of the apparatus or methodrealizations, or a combination thereof, may be utilized, for example andwithout limitation, while aircraft 1102 is in service (block 1114)and/or during maintenance and service (block 1116).

Different examples of the apparatus(es) and method(s) disclosed hereininclude a variety of components, features, and functionalities. Itshould be understood that the various examples of the apparatus(es) andmethod(s) disclosed herein may include any of the components, features,and functionalities of any of the other examples of the apparatus(es)and method(s) disclosed herein in any combination, and all of suchpossibilities are intended to be within the scope of the presentdisclosure.

Many modifications of examples set forth herein will come to mind to oneskilled in the art to which the present disclosure pertains having thebenefit of the teachings presented in the foregoing descriptions and theassociated drawings.

Therefore, it is to be understood that the present disclosure is not tobe limited to the specific examples illustrated and that modificationsand other examples are intended to be included within the scope of theappended claims. Moreover, although the foregoing description and theassociated drawings describe examples of the present disclosure in thecontext of certain illustrative combinations of elements and/orfunctions, it should be appreciated that different combinations ofelements and/or functions may be provided by alternative implementationswithout departing from the scope of the appended claims. Accordingly,parenthetical reference numerals in the appended claims are presentedfor illustrative purposes only and are not intended to limit the scopeof the claimed subject matter to the specific examples provided in thepresent disclosure.

1. A stiffener (100) comprising: a first stiffener portion (102) havinga first cross-sectional profile (104) that is constant along the firststiffener portion (102); a second stiffener portion (106) having asecond cross-sectional profile (108) that is constant along the secondstiffener portion (106), wherein the second cross-sectional profile(108) of the second stiffener portion (106) is different from the firstcross-sectional profile (104) of the first stiffener portion (102); anda transition stiffener portion (110) tapering from the second stiffenerportion (106) to the first stiffener portion (102). 2-4. (canceled) 5.The stiffener (100) according to claim 1, wherein: the transitionstiffener portion (110) comprises transition cross-sectional profiles(112), and the transitional cross-sectional profiles (112) of thetransition stiffener portion (110) are different from the firstcross-sectional profile (104) of the first stiffener portion (102) andthe second cross-sectional profile (108) of the second stiffener portion(106). 6-7. (canceled)
 8. The stiffener (100) according to claim 1,further comprising charges (160) laminated together to form the firststiffener portion (102), a part of the second stiffener portion (106),and a part of the transition stiffener portion (110).
 9. The stiffener(100) according to claim 8, further comprising prepreg composite plies(126) laminated together to form each one of the charges (160), wherein:the prepreg composite plies (126) comprise reinforcement fibers (240),the reinforcement fibers (240) of approximately fifty percent of theprepreg composite plies (126) are parallel to a primary load directionof the stiffener (100), the reinforcement fibers (240) of approximatelyforty percent of the prepreg composite plies (126) are at forty-fivedegrees to the primary load direction of the stiffener (100), and thereinforcement fibers (240) of approximately ten percent of the prepregcomposite plies (126) are perpendicular to the primary load direction ofthe stiffener (100).
 10. The stiffener (100) according to claim 8,further comprising a web (120), wherein: a part of the second stiffenerportion (106) and a part of the transition stiffener portion (110) areformed by the web (120), the web (120) comprises a base (122) and a rib(168) perpendicular to the base (122), and the base (122) of the web(120) is parallel to the charges (160).
 11. The stiffener (100)according to claim 10, wherein the web (120) tapers from the secondstiffener portion (106) to the first stiffener portion (102).
 12. Thestiffener (100) according to claim 10, wherein: one of the charges (160)has a width W1 that gradually decreases along the transition stiffenerportion (110) from the second stiffener portion (106) to the firststiffener portion (102), and the charges (160) have a combined height H1that gradually increases along the transition stiffener portion (110)from the second stiffener portion (106) to the first stiffener portion(102).
 13. The stiffener (100) according to claim 12, wherein: the base(122) of the web (120) has a width W2 that progressively decreases alongthe transition stiffener portion (110) from the second stiffener portion(106) to the first stiffener portion (102), and the rib (168) of the web(120) has a height H2 that progressively decreases along the transitionstiffener portion (110) from the second stiffener portion (106) to thefirst stiffener portion (102).
 14. The stiffener (100) according toclaim 1, further comprising: a base charge (124) comprising a firstbase-charge portion (142), a second base-charge portion (144), and atransition base-charge portion (146), wherein: a part of the firststiffener portion (102) is formed by the first base-charge portion(142); a part of the second stiffener portion (106) is formed by thesecond base-charge portion (144); a part of the transition stiffenerportion (110) is formed by the transition base-charge portion (146), andthe transition base-charge portion (146) of the base charge (124) tapersfrom the second base-charge portion (144) to the first base-chargeportion (142); an initial charge (148) laminated onto the base charge(124), wherein: the initial charge (148) comprises a firstinitial-charge portion (150) and a transition initial-charge portion(152), a part of the first stiffener portion (102) is formed by thefirst initial-charge portion (150), a part of the transition stiffenerportion (110) is formed by the transition initial-charge portion (152),and the first initial-charge portion (150) of the initial charge (148)is shaped identically to the first base-charge portion (142) of the basecharge (124) and the transition initial-charge portion (152) of theinitial charge (148) is shaped identically to at least a portion of thetransition base-charge portion (146) of the base charge (124); and asubsequent charge A laminated onto the initial charge (148), wherein:the subsequent charge A comprises a first subsequent-charge-A portionand a transition subsequent-charge-A portion, a part of the firststiffener portion (102) is formed by the first subsequent-charge-Aportion, a part of the transition stiffener portion (110) is formed bythe transition subsequent-charge-A portion, and the firstsubsequent-charge-A portion of the subsequent charge A is shapedidentically to the first initial-charge portion (150) of the initialcharge (148) and the transition subsequent-charge-A portion of thesubsequent charge A is smaller than the transition initial-chargeportion (152) of the initial charge (148) and is shaped identically to aportion of the transition initial-charge portion (152).
 15. Thestiffener (100) according to claim 14, further comprising a web (120),wherein a part of the second stiffener portion (106) and a part of thetransition stiffener portion (110) are formed by the web (120).
 16. Thestiffener (100) according to claim 15, further comprising a cover layer(176) between the web (120) and the subsequent charge A, the initialcharge (148), and the base charge (124), wherein the cover layer (176)covers: the first stiffener portion (102), formed, at least partially,by the first base-charge portion (142) of the base charge (124), thefirst initial-charge portion (150) of the initial charge (148), and thefirst subsequent-charge-A portion of the subsequent charge A; a part ofthe transition stiffener portion (110), formed, at least partially, bythe transition base-charge portion (146) of the base charge (124), thetransition initial-charge portion (152) of the initial charge (148), andthe transition subsequent-charge-A portion of the subsequent charge A;and a part of the second stiffener portion (106), formed, at leastpartially, by the second base-charge portion (144) of the base charge(124).
 17. The stiffener (100) according to claim 15, wherein the web(120) comprises: a web charge (178) comprising a second web-chargeportion (180) and a transition web-charge portion (182), wherein: a partof the second stiffener portion (106) is formed by the second web-chargeportion (180), and a part of the transition stiffener portion (110) isformed by the transition web-charge portion (182); and an opposing webcharge (184) abutting a portion of the web charge (178) and comprising asecond opposing-web-charge portion (186) and a transitionopposing-web-charge portion (188), wherein: a part of the secondstiffener portion (106) is formed by the second opposing-web-chargeportion (186), and a part of the transition stiffener portion (110) isformed by the transition opposing-web-charge portion (188). 18.(canceled)
 19. The stiffener (100) according to claim 17, wherein thetransition web-charge portion (182) of the web charge (178) and thetransition opposing-web-charge portion (188) of the opposing web charge(184) taper from the second stiffener portion (106) to the firststiffener portion (102).
 20. The stiffener (100) according to claim 17,wherein each of the web charge (178) and the opposing web charge (184)is L-shaped.
 21. The stiffener (100) according to claim 17, wherein eachof the web charge (178) and the opposing web charge (184) is U-shaped.22. The stiffener (100) according to claim 21, further comprising a capcharge (190) laminated onto portions of the web charge (178) and theopposing web charge (184), wherein the cap charge (190) forms a part ofthe second stiffener portion (106) and a part of the transitionstiffener portion (110).
 23. The stiffener (100) according to claim 17,further comprising a filler charge (192) between the web charge (178)and the opposing web charge (184), wherein: the filler charge (192)comprises a second filler-charge portion (194) and a transitionfiller-charge portion (196), a part of the second stiffener portion(106) is formed by the second filler-charge portion (194), and a part ofthe transition stiffener portion (110) is formed by the transitionfiller-charge portion (196).
 24. The stiffener (100) according to claim14, further comprising a subsequent charge B laminated onto thesubsequent charge A, wherein: the subsequent charge B comprises a firstsubsequent-charge-B portion, forming a part of the first stiffenerportion (102), and a transition subsequent-charge-B portion, forming apart of the transition stiffener portion (110), the firstsubsequent-charge-B portion of the subsequent charge B is shapedidentically to the first subsequent-charge-A portion of the subsequentcharge A, and the transition subsequent-charge-B portion of thesubsequent charge B is smaller than the transition subsequent-charge-Aportion of the subsequent charge A and is shaped identically to aportion of the transition subsequent-charge-A portion.
 25. (canceled)26. A structure (200) comprising: a skin (202) comprising a surface(204); and a stiffener (100) coupled to the surface (204) of the skin(202), wherein the stiffener (100) comprises: a first stiffener portion(102) having a first cross-sectional profile (104) that is constantalong the first stiffener portion (102); a second stiffener portion(106) having a second cross-sectional profile (108) that is constantalong the second stiffener portion (106), wherein the secondcross-sectional profile (108) of the second stiffener portion (106) isdifferent from the first cross-sectional profile (104) of the firststiffener portion (102); and a transition stiffener portion (110)tapering from the second stiffener portion (106) to the first stiffenerportion (102). 27-63. (canceled)
 64. A method (300) of making astiffener (100), the method (300) comprising: laying up a base charge(124) to form a part of a first stiffener portion (102) of the stiffener(100) from a first base-charge portion (142) of the base charge (124),to form a part of a second stiffener portion (106) of the stiffener(100) from a second base-charge portion (144) of the base charge (124),and to form a part of a transition stiffener portion (110) of thestiffener (100) from a transition base-charge portion (146) of the basecharge (124), wherein the transition base-charge portion (146) tapersfrom the second base-charge portion (144) to the first base-chargeportion (142); laminating an initial charge (148) onto the base charge(124) to form a part of the first stiffener portion (102) of thestiffener (100) from a first initial-charge portion (150) of the initialcharge (148) and to form a part of the transition stiffener portion(110) of the stiffener (100) from a transition initial-charge portion(152) of the initial charge (148), wherein the first initial-chargeportion (150) of the initial charge (148) is shaped identically to thefirst base-charge portion (142) of the base charge (124) and thetransition initial-charge portion (152) of the initial charge (148) isshaped identically to at least a portion of the transition base-chargeportion (146) of the base charge (124); and laminating a subsequentcharge A onto the initial charge (148) to form a part of the firststiffener portion (102) of the stiffener (100) from a firstsubsequent-charge-A portion of the subsequent charge A and to form apart of the transition stiffener portion (110) of the stiffener (100)from a transition subsequent-charge-A portion of the subsequent chargeA, wherein the first subsequent-charge-A portion of the subsequentcharge A is shaped identically to the first initial-charge portion (150)of the initial charge (148) and the transition subsequent-charge-Aportion of the subsequent charge A is smaller than the transitioninitial-charge portion (152) of the initial charge (148) and is shapedidentically to a portion of the transition initial-charge portion (152).65-72. (canceled)